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