diff --git a/src/app/core/header/header.scss b/src/app/core/header/header.scss
index f6006d2..2db767c 100644
--- a/src/app/core/header/header.scss
+++ b/src/app/core/header/header.scss
@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
+@import './../../style/vars.scss';
 
 #toast-container [toast]:not(:first-child) {
   margin-top: 10px !important;
@@ -41,6 +41,7 @@
     background: #2a2d35 !important;
     min-width: 300px;
 
+    /* service status */
     .table {
       margin-bottom: 0;
     }
@@ -52,6 +53,20 @@
     .table tr th:last-child {
       padding-right: 20px;
     }
+
+    /* search bar */
+
+    li.uib-typeahead-match > a {
+      color: #ccc;
+    }
+
+    li.uib-typeahead-match.active > a,
+    li.uib-typeahead-match.active > a:hover,
+    li.uib-typeahead-match.active > a:focus {
+      font-weight: bold;
+      background-color: rgba(68, 70, 79, 0.5);
+      color: #fff;
+    }
   }
 
   .navbar-nav a {
@@ -61,7 +76,8 @@
   .navbar-nav > .open > a,
   .navbar-nav > .open > a:hover {
     color:#ffffff !important;
-    background-color:rgba(246,168,33,0.1) !important;;
+    background-color:rgba(246,168,33,0.1) !important;
     border-color:#f6a821;
   }
+
 }
\ No newline at end of file
diff --git a/src/app/core/loader/loader.scss b/src/app/core/loader/loader.scss
new file mode 100644
index 0000000..0f7021a
--- /dev/null
+++ b/src/app/core/loader/loader.scss
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+xos-loader {
+  .alert.alert-danger {
+    margin-top: 100px;
+
+    .fa.fa-exclamation-triangle {
+      font-size: 40px;
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/app/core/loader/loader.spec.ts b/src/app/core/loader/loader.spec.ts
index 44fc60f..0744c11 100644
--- a/src/app/core/loader/loader.spec.ts
+++ b/src/app/core/loader/loader.spec.ts
@@ -77,86 +77,116 @@
     timeout = $timeout;
     location = $location;
     spyOn(location, 'path');
-
-    MockDiscover.discover = jasmine.createSpy('discover')
-      .and.callFake(() => {
-        const d = $q.defer();
-        d.resolve(true);
-        return d.promise;
-      });
-
-    MockOnboarder.onboard = jasmine.createSpy('onboard')
-      .and.callFake(() => {
-        const d = $q.defer();
-        d.resolve();
-        return d.promise;
-      });
   }));
 
-  describe('when models are already loaded', () => {
-
-    beforeEach(() => {
-      compileElement();
-      spyOn(isolatedScope, 'moveOnTo');
-      isolatedScope.run();
-      timeout.flush();
-    });
-
-    it('should redirect to the last visited page', (done) => {
-      window.setTimeout(() => {
-        expect(isolatedScope.moveOnTo).toHaveBeenCalledWith('/test');
-        expect(location.path).toHaveBeenCalledWith('/test');
-        done();
-      }, 600);
-    });
-  });
-
-  describe('when the last visited page is "loader"', () => {
-
-    beforeEach(() => {
-      MockConfig.lastVisitedUrl = '/loader';
-      compileElement();
-      spyOn(isolatedScope, 'moveOnTo');
-      isolatedScope.run();
-    });
-
-    it('should redirect to the "dashboard" page', (done) => {
-      window.setTimeout(() => {
-        expect(isolatedScope.moveOnTo).toHaveBeenCalledWith('/loader');
-        expect(location.path).toHaveBeenCalledWith('/dashboard');
-        done();
-      }, 600);
-    });
-  });
-
-  describe('when user is not authenticated', () => {
-
-    beforeEach(() => {
+  describe('when chameleon is not responding', () => {
+    beforeEach(inject(($q: ng.IQService) => {
       loaded = false;
-      authenticated = false;
-      compileElement();
-      isolatedScope.run();
-    });
-
-    it('should redirect to the login page', () => {
-      expect(MockState.go).toHaveBeenCalledWith('xos.login');
-    });
-
-    afterEach(() => {
       authenticated = true;
+      MockDiscover.discover = jasmine.createSpy('discover')
+        .and.callFake(() => {
+          const d = $q.defer();
+          d.resolve('chameleon');
+          return d.promise;
+        });
+      compileElement();
+      spyOn(isolatedScope, 'moveOnTo');
+      isolatedScope.run();
+    }));
+
+    it('should print an error', () => {
+      expect(isolatedScope.moveOnTo).not.toHaveBeenCalled();
+      expect(isolatedScope.error).toBe('chameleon');
+      expect(isolatedScope.loader).toBeFalsy();
     });
   });
 
-  describe('when models are not loaded', () => {
+  describe('when chameleon is available', () => {
 
-    beforeEach(() => {
-      loaded = false;
-      compileElement();
-      spyOn(isolatedScope, 'moveOnTo');
+    beforeEach(inject(($q: ng.IQService) => {
+      loaded = true;
+      authenticated = true;
+      MockDiscover.discover = jasmine.createSpy('discover')
+        .and.callFake(() => {
+          const d = $q.defer();
+          d.resolve(true);
+          return d.promise;
+        });
+
+      MockOnboarder.onboard = jasmine.createSpy('onboard')
+        .and.callFake(() => {
+          const d = $q.defer();
+          d.resolve();
+          return d.promise;
+        });
+    }));
+
+    describe('when models are already loaded', () => {
+
+      beforeEach(() => {
+        compileElement();
+        spyOn(isolatedScope, 'moveOnTo');
+        isolatedScope.run();
+        timeout.flush();
+      });
+
+      it('should redirect to the last visited page', (done) => {
+        window.setTimeout(() => {
+          expect(isolatedScope.moveOnTo).toHaveBeenCalledWith('/test');
+          expect(location.path).toHaveBeenCalledWith('/test');
+          done();
+        }, 600);
+      });
     });
 
-    it('should call XosModelDiscoverer.discover', () => {
-      expect(MockDiscover.discover).toHaveBeenCalled();
+    describe('when the last visited page is "loader"', () => {
+
+      beforeEach(() => {
+        MockConfig.lastVisitedUrl = '/loader';
+        compileElement();
+        spyOn(isolatedScope, 'moveOnTo');
+        isolatedScope.run();
+      });
+
+      it('should redirect to the "dashboard" page', (done) => {
+        window.setTimeout(() => {
+          expect(isolatedScope.moveOnTo).toHaveBeenCalledWith('/loader');
+          expect(location.path).toHaveBeenCalledWith('/dashboard');
+          done();
+        }, 600);
+      });
+    });
+
+    describe('when user is not authenticated', () => {
+
+      beforeEach(() => {
+        loaded = false;
+        authenticated = false;
+        compileElement();
+        isolatedScope.run();
+      });
+
+      it('should redirect to the login page', () => {
+        expect(MockState.go).toHaveBeenCalledWith('xos.login');
+      });
+
+      afterEach(() => {
+        authenticated = true;
+      });
+    });
+
+    describe('when models are not loaded', () => {
+
+      beforeEach(() => {
+        loaded = false;
+        authenticated = true;
+        compileElement();
+        spyOn(isolatedScope, 'moveOnTo');
+      });
+
+      it('should call XosModelDiscoverer.discover', () => {
+        expect(MockDiscover.discover).toHaveBeenCalled();
+      });
     });
   });
 
diff --git a/src/app/core/loader/loader.ts b/src/app/core/loader/loader.ts
index b93aebf..3606ca8 100644
--- a/src/app/core/loader/loader.ts
+++ b/src/app/core/loader/loader.ts
@@ -19,6 +19,8 @@
 import {IXosModelDiscovererService} from '../../datasources/helpers/model-discoverer.service';
 import {IXosOnboarder} from '../../extender/services/onboard.service';
 import {IXosAuthService} from '../../datasources/rest/auth.rest';
+import './loader.scss';
+
 class LoaderCtrl {
   static $inject = [
     '$log',
@@ -32,6 +34,9 @@
     `XosOnboarder`
   ];
 
+  public loader: boolean = true;
+  public error: string;
+
   constructor (
     private $log: ng.ILogService,
     private $rootScope: ng.IScope,
@@ -49,26 +54,45 @@
 
   public run() {
     if (this.XosModelDiscoverer.areModelsLoaded()) {
+      this.$log.debug(`[XosLoader] Models are already loaded, moving to: ${this.XosConfig.lastVisitedUrl}`);
       this.moveOnTo(this.XosConfig.lastVisitedUrl);
     }
     else if (!this.XosAuthService.isAuthenticated()) {
+      this.$log.debug(`[XosLoader] Not authenticated, send to login`);
       this.$state.go('xos.login');
     }
     else {
       // NOTE loading XOS Models
       this.XosModelDiscoverer.discover()
         .then((res) => {
-          if (res) {
+          this.$log.info('[XosLoader] res: ' + res, res, typeof res);
+          if (res === 'chameleon') {
+            this.loader = false;
+            this.error = 'chameleon';
+            return 'chameleon';
+          }
+          else if (res) {
             this.$log.info('[XosLoader] All models loaded');
+            // NOTE loading GUI Extensions
+            this.XosOnboarder.onboard();
+            return true;
           }
           else {
             this.$log.info('[XosLoader] Failed to load some models, moving on.');
+            return true;
           }
-          // NOTE loading GUI Extensions
-          return this.XosOnboarder.onboard();
         })
-        .then(() => {
-          this.moveOnTo(this.XosConfig.lastVisitedUrl);
+        .then((res) => {
+          if (res === true) {
+            this.moveOnTo(this.XosConfig.lastVisitedUrl);
+          }
+          // NOTE otherwise stay here since we're printing some error messages
+        })
+        .catch(() => {
+          // XosModelDiscoverer.discover reject only in case of authentication error
+          this.XosAuthService.clearUser();
+          this.moveOnTo('/login');
+
         })
         .finally(() => {
           // NOTE it is in a timeout as the searchService is loaded after that
@@ -99,7 +123,22 @@
 
 export const xosLoader: angular.IComponentOptions = {
   template: `
-    <div class="loader"></div>
+    <div ng-show="vm.loader" class="loader"></div>
+    <div class="row" ng-show="vm.error == 'chameleon'">
+      <div class="col-sm-6 col-sm-offset-3">
+        <div class="alert alert-danger">
+          <div class="row">
+            <div class="col-xs-2">
+              <i class="fa fa-exclamation-triangle"></i>
+            </div>
+            <div class="col-xs-10">
+              <strong>Cannot load models definition.</strong><br>
+              Please check that the Chameleon container is running
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
   `,
   controllerAs: 'vm',
   controller: LoaderCtrl
diff --git a/src/app/datasources/helpers/model-discoverer.service.ts b/src/app/datasources/helpers/model-discoverer.service.ts
index fca593c..3ee5a15 100644
--- a/src/app/datasources/helpers/model-discoverer.service.ts
+++ b/src/app/datasources/helpers/model-discoverer.service.ts
@@ -44,7 +44,7 @@
 
 // Service
 export interface IXosModelDiscovererService {
-  discover(): ng.IPromise<boolean>;
+  discover(): ng.IPromise<string>;
   getApiUrlFromModel(model: IXosModel): string;
   areModelsLoaded(): boolean;
 }
@@ -127,28 +127,42 @@
               return this.$q.resolve('true');
             })
             .catch(err => {
-              this.$log.error(`[XosModelDiscovererService] Model ${model.name} NOT stored`, err);
+              this.$log.warn(`[XosModelDiscovererService] Model ${model.name} NOT stored`, err);
+              const isAuthError = this.AuthService.isAuthError(err);
+              if (isAuthError) {
+                this.$log.warn(`[XosModelDiscovererService] User is not authentincated`);
+                return this.$q.reject(err);
+              }
               return this.$q.resolve('false');
             });
             pArray.push(p);
         });
+
+
         this.$q.all(pArray)
           .then((res) => {
-            // the Model Loader promise won't ever be reject, in case it will be resolve with value false,
+            // the ModelLoader promise won't ever be reject, in case it will be resolve with value false,
             // that's because we want to wait anyway for all the models to be loaded
             if (res.indexOf('false') > -1) {
               return d.resolve(false);
             }
             d.resolve(true);
+            this.modelsLoaded = true;
           })
           .catch((e) => {
-            this.$log.error(`[XosModelDiscovererService]`, e);
-            d.resolve(false);
+            this.XosModelStore.clean(); // reset all the observable otherwise they'll store login errors
+            this.$log.warn(`[XosModelDiscovererService]`, e);
+            // the ModelLoader promise will be rejected in case of authentication error
+            d.reject(e);
           })
           .finally(() => {
             this.progressBar.complete();
-            this.modelsLoaded = true;
           });
+      })
+      .catch(err => {
+        this.progressBar.complete();
+        this.$log.error(`[XosModelDiscovererService] Cannot load model defs`, err);
+        return d.resolve('chameleon');
       });
     return d.promise;
   }
@@ -249,16 +263,17 @@
   }
 
   private cacheModelEntries(model: IXosModel): ng.IPromise<IXosModel> {
+
     const d = this.$q.defer();
 
     const apiUrl = this.getApiUrlFromModel(model);
     this.XosModelStore.query(model.name, apiUrl)
+      .skip(1) // NOTE observables returns as first an empty array, so skip it
       .subscribe(
         () => {
           return d.resolve(model);
         },
         err => {
-          this.AuthService.handleUnauthenticatedRequest(err);
           return d.reject(err);
         }
       );
diff --git a/src/app/datasources/helpers/model.discoverer.service.spec.ts b/src/app/datasources/helpers/model.discoverer.service.spec.ts
index a6e6340..5deb444 100644
--- a/src/app/datasources/helpers/model.discoverer.service.spec.ts
+++ b/src/app/datasources/helpers/model.discoverer.service.spec.ts
@@ -73,9 +73,13 @@
 };
 const MockXosModelStore = {
   query: jasmine.createSpy('modelStore.query')
-    .and.callFake(() => {
+    .and.callFake((model) => {
       const list = new BehaviorSubject([]);
       list.next([]);
+      window.setTimeout(() => {
+        // NOTE force the Observable to call next two times, as cacheModelEntries is not caching the first result (since it's generated)
+        list.next([]);
+      }, 100);
       return list.asObservable();
     })
 };
@@ -165,6 +169,22 @@
     expect(service['getParentStateFromModel']({name: 'Tenant', app: 'services.vsg'})).toBe('xos.vsg');
   });
 
+  it('should add an item to navigation', () => {
+    service['addNavItem']({name: 'Tenant', app: 'services.vsg'});
+    expect(MockXosNavigationService.add).toHaveBeenCalledWith({
+      label: 'Tenants',
+      state: 'xos.vsg.tenant',
+      parent: 'xos.vsg'
+    });
+
+    service['addNavItem']({name: 'Tenant', verbose_name: 'Verbose', app: 'services.vsg'});
+    expect(MockXosNavigationService.add).toHaveBeenCalledWith({
+      label: 'Verboses',
+      state: 'xos.vsg.tenant',
+      parent: 'xos.vsg'
+    });
+  });
+
   it('should add a new service entry in the system', () => {
     service['addService']({name: 'Tenant', app: 'services.vsg'});
     expect(MockXosRuntimeStates.addState).toHaveBeenCalledWith('xos.vsg', {
@@ -226,22 +246,6 @@
     scope.$apply();
   });
 
-  it('should add an item to navigation', () => {
-    service['addNavItem']({name: 'Tenant', app: 'services.vsg'});
-    expect(MockXosNavigationService.add).toHaveBeenCalledWith({
-      label: 'Tenants',
-      state: 'xos.vsg.tenant',
-      parent: 'xos.vsg'
-    });
-
-    service['addNavItem']({name: 'Tenant', verbose_name: 'Verbose', app: 'services.vsg'});
-    expect(MockXosNavigationService.add).toHaveBeenCalledWith({
-      label: 'Verboses',
-      state: 'xos.vsg.tenant',
-      parent: 'xos.vsg'
-    });
-  });
-
   it('should cache a model', () => {
     service['cacheModelEntries']({name: 'Tenant', app: 'services.vsg'});
     expect(MockXosModelStore.query).toHaveBeenCalledWith('Tenant', '/vsg/tenants');
@@ -276,7 +280,7 @@
       service.discover()
         .then((res) => {
           expect(MockProgressBar.start).toHaveBeenCalled();
-          expect(MockXosModelDefs.get).toHaveBeenCalled(); // FIXME replace correct spy
+          expect(MockXosModelDefs.get).toHaveBeenCalled();
           expect(service['cacheModelEntries'].calls.count()).toBe(2);
           expect(service['addState'].calls.count()).toBe(2);
           expect(service['addNavItem'].calls.count()).toBe(2);
@@ -287,6 +291,10 @@
           done();
         });
       scope.$apply();
+      window.setTimeout(() => {
+        // resolve promises after the observable.next as been called twice (cacheModelEntries requires it)
+        scope.$apply();
+      }, 101);
     });
   });
 });
diff --git a/src/app/datasources/rest/auth.rest.spec.ts b/src/app/datasources/rest/auth.rest.spec.ts
index 8ba77d3..044cf88 100644
--- a/src/app/datasources/rest/auth.rest.spec.ts
+++ b/src/app/datasources/rest/auth.rest.spec.ts
@@ -106,36 +106,36 @@
     });
   });
 
-  describe('the handleUnauthenticatedRequest method', () => {
+  describe('the isAuthError method', () => {
 
     beforeEach(() => {
       spyOn(service, 'clearUser');
     });
 
     it('should logout the user and redirect to login', () => {
-      service.handleUnauthenticatedRequest({
+      let res = service.isAuthError({
         error: 'XOSPermissionDenied',
         fields: {},
         specific_error: 'test'
       });
-      expect(service.clearUser).toHaveBeenCalled();
+      expect(res).toBeTruthy();
     });
 
     it('should catch errors from strings', () => {
-      service.handleUnauthenticatedRequest('{"fields": {}, "specific_error": "failed to authenticate token g09et150o2s25kdzg8t2n9wotvds9jyl", "error": "XOSPermissionDenied"}');
-      expect(service.clearUser).toHaveBeenCalled();
+      let res = service.isAuthError('{"fields": {}, "specific_error": "failed to authenticate token g09et150o2s25kdzg8t2n9wotvds9jyl", "error": "XOSPermissionDenied"}');
+      expect(res).toBeTruthy();
     });
 
     it('should not catch other errors', () => {
-      service.handleUnauthenticatedRequest({
+      let res = service.isAuthError({
         error: 'XOSProgrammingError',
         fields: {},
         specific_error: 'test'
       });
-      expect(service.clearUser).not.toHaveBeenCalled();
+      expect(res).toBeFalsy();
 
-      service.handleUnauthenticatedRequest('some error');
-      expect(service.clearUser).not.toHaveBeenCalled();
+      res = service.isAuthError('some error');
+      expect(res).toBeFalsy();
     });
   });
 });
diff --git a/src/app/datasources/rest/auth.rest.ts b/src/app/datasources/rest/auth.rest.ts
index 2bc2bbc..0c202b0 100644
--- a/src/app/datasources/rest/auth.rest.ts
+++ b/src/app/datasources/rest/auth.rest.ts
@@ -46,7 +46,7 @@
   getUser(): any; // NOTE how to define return user || false ???
   isAuthenticated(): boolean;
   clearUser(): void;
-  handleUnauthenticatedRequest(error: IXosRestError | string): void;
+  isAuthError(error: IXosRestError | string): boolean;
 }
 export class AuthService {
 
@@ -111,7 +111,7 @@
     return angular.isDefined(session);
   }
 
-  public handleUnauthenticatedRequest(res: IXosRestError | string): void {
+  public isAuthError(res: IXosRestError | string): boolean {
     let err;
     if (angular.isString(res)) {
       try {
@@ -129,9 +129,7 @@
     if (err && err.error) {
       switch (err.error) {
         case 'XOSPermissionDenied':
-          this.clearUser();
-          this.$state.go('login');
-          break;
+          return true;
       }
     }
   }
diff --git a/src/app/datasources/rest/modeldefs.rest.ts b/src/app/datasources/rest/modeldefs.rest.ts
index 60fc917..38ffb16 100644
--- a/src/app/datasources/rest/modeldefs.rest.ts
+++ b/src/app/datasources/rest/modeldefs.rest.ts
@@ -18,6 +18,7 @@
 
 import {IXosModelDefsField} from '../../core/services/helpers/config.helpers';
 import {IXosAppConfig} from '../../../index';
+import IPromise = angular.IPromise;
 
 export interface IXosModelDefsRelation {
   model: string; // model name
@@ -35,7 +36,7 @@
 }
 
 export interface IXosModeldefsService {
-  get(): Promise<IXosModeldef[]>;
+  get(): IPromise<IXosModeldef[]>;
 }
 
 export class XosModeldefsService implements IXosModeldefsService {
@@ -49,9 +50,9 @@
   ) {
   }
 
-  public get(): Promise<any> {
+  public get(): IPromise<IXosModeldef[]> {
     const d = this.$q.defer();
-    this.$http.get(`${this.AppConfig.apiEndpoint}/modeldefs`)
+    this.$http.get(`${this.AppConfig.apiEndpoint}/modeldefs`, {timeout: 5 * 1000})
       .then((res: any) => {
         d.resolve(res.data.items);
       })
diff --git a/src/app/datasources/stores/model.store.ts b/src/app/datasources/stores/model.store.ts
index 4f430e6..b26c262 100644
--- a/src/app/datasources/stores/model.store.ts
+++ b/src/app/datasources/stores/model.store.ts
@@ -29,6 +29,7 @@
   query(model: string, apiUrl?: string): Observable<any>;
   get(model: string, id: string | number): Observable<any>;
   search(modelName: string): any[];
+  clean(): void;
 }
 
 export class XosModelStore implements IXosModelStoreService {
@@ -54,6 +55,10 @@
     this.efficientNext = this.XosDebouncer.debounce(this.next, 500, this, false);
   }
 
+  public clean() {
+    this._collections = {};
+  }
+
   public query(modelName: string, apiUrl?: string): Observable<any> {
     this.$log.debug(`[XosModelStore] QUERY: ${modelName}`);
     // if there isn't already an observable for that item
diff --git a/src/interceptors.ts b/src/interceptors.ts
index 7473226..616063b 100644
--- a/src/interceptors.ts
+++ b/src/interceptors.ts
@@ -26,13 +26,17 @@
 
 export function userStatusInterceptor($state: angular.ui.IStateService, $cookies: ng.cookies.ICookiesService, $q: ng.IQService) {
   const checkLogin = (res) => {
+
+    // NOTE canceled request (as the modeldefs one) have no res
+    if (angular.isUndefined(res) || res === null) {
+      return $q.reject(res);
+    }
+
     // NOTE this interceptor may never be called as the request is not rejected byt the "model-discoverer" service
     switch (res.status) {
-      case -1:
       case 401:
       case 403:
         $cookies.remove('sessionid', {path: '/'});
-        $state.go('login');
         return $q.reject(res);
       default:
         return $q.reject(res);