diff --git a/ui-ngx/src/app/core/services/dialog.service.ts b/ui-ngx/src/app/core/services/dialog.service.ts
index 6d664085b1..be0c24a958 100644
--- a/ui-ngx/src/app/core/services/dialog.service.ts
+++ b/ui-ngx/src/app/core/services/dialog.service.ts
@@ -29,6 +29,7 @@ import {
 } from '@shared/components/dialog/material-icons-dialog.component';
 import { ConfirmDialogComponent } from '@shared/components/dialog/confirm-dialog.component';
 import { AlertDialogComponent } from '@shared/components/dialog/alert-dialog.component';
+import { ErrorAlertDialogComponent } from '@shared/components/dialog/error-alert-dialog.component';
 import { TodoDialogComponent } from '@shared/components/dialog/todo-dialog.component';
 
 @Injectable(
@@ -78,6 +79,23 @@ export class DialogService {
     return dialogRef.afterClosed();
   }
 
+  errorAlert(title: string, message: string, error: any, ok: string = null, fullscreen: boolean = false): Observable<any> {
+    const dialogConfig: MatDialogConfig = {
+      disableClose: true,
+      data: {
+        title,
+        message,
+        error,
+        ok: ok || this.translate.instant('action.ok')
+      }
+    };
+    if (fullscreen) {
+      dialogConfig.panelClass = ['tb-fullscreen-dialog'];
+    }
+    const dialogRef = this.dialog.open(ErrorAlertDialogComponent, dialogConfig);
+    return dialogRef.afterClosed();
+  }
+
   colorPicker(color: string): Observable<string> {
     return this.dialog.open<ColorPickerDialogComponent, ColorPickerDialogData, string>(ColorPickerDialogComponent,
       {
diff --git a/ui-ngx/src/app/core/services/utils.service.ts b/ui-ngx/src/app/core/services/utils.service.ts
index 813127cbc5..f82c6c3072 100644
--- a/ui-ngx/src/app/core/services/utils.service.ts
+++ b/ui-ngx/src/app/core/services/utils.service.ts
@@ -188,6 +188,10 @@ export class UtilsService {
 
   public processWidgetException(exception: any): ExceptionData {
     const data = this.parseException(exception, -6);
+    if (data.message?.startsWith('NG0')) {
+       data.message = `${this.translate.instant('widget.widget-template-error')}<br/>
+                       <br/><i>${this.translate.instant('dialog.error-message-title')}</i><br/><br/>${data.message}`;
+    }
     if (this.widgetEditMode) {
       const message: WindowMessage = {
         type: 'widgetException',
diff --git a/ui-ngx/src/app/modules/home/components/widget/dialog/custom-dialog-container.component.ts b/ui-ngx/src/app/modules/home/components/widget/dialog/custom-dialog-container.component.ts
index d9ab65813f..dc3e9c7ac2 100644
--- a/ui-ngx/src/app/modules/home/components/widget/dialog/custom-dialog-container.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/dialog/custom-dialog-container.component.ts
@@ -33,6 +33,8 @@ import {
   CustomDialogComponent,
   CustomDialogData
 } from '@home/components/widget/dialog/custom-dialog.component';
+import { DialogService } from '@core/services/dialog.service';
+import { TranslateService } from '@ngx-translate/core';
 
 export interface CustomDialogContainerData {
   controller: (instance: CustomDialogComponent) => void;
@@ -54,6 +56,8 @@ export class CustomDialogContainerComponent extends DialogComponent<CustomDialog
               protected router: Router,
               public viewContainerRef: ViewContainerRef,
               public dialogRef: MatDialogRef<CustomDialogContainerComponent>,
+              private dialogService: DialogService,
+              private translate: TranslateService,
               @Inject(MAT_DIALOG_DATA) public data: CustomDialogContainerData) {
     super(store, router, dialogRef);
     let customDialogData: CustomDialogData = {
@@ -72,7 +76,19 @@ export class CustomDialogContainerComponent extends DialogComponent<CustomDialog
           useValue: dialogRef
         }]
     });
-    this.customComponentRef = this.viewContainerRef.createComponent(this.data.customComponentFactory, 0, injector);
+    try {
+      this.customComponentRef = this.viewContainerRef.createComponent(this.data.customComponentFactory, 0, injector);
+    } catch (e: any) {
+      let message;
+      if (e.message?.startsWith('NG0')) {
+        message = this.translate.instant('widget-action.custom-pretty-template-error');
+      } else {
+        message = this.translate.instant('widget-action.custom-pretty-controller-error');
+      }
+      dialogRef.close();
+      console.error(e);
+      this.dialogService.errorAlert(this.translate.instant('widget-action.custom-pretty-error-title'), message, e);
+    }
   }
 
   ngOnDestroy(): void {
diff --git a/ui-ngx/src/app/modules/home/components/widget/widget.component.html b/ui-ngx/src/app/modules/home/components/widget/widget.component.html
index 0f8f6a9997..ce5a5a57e7 100644
--- a/ui-ngx/src/app/modules/home/components/widget/widget.component.html
+++ b/ui-ngx/src/app/modules/home/components/widget/widget.component.html
@@ -34,7 +34,7 @@
   </tb-legend>
 </div>
 <div class="tb-absolute-fill tb-widget-error" *ngIf="widgetErrorData">
-  <span>Widget Error: {{ widgetErrorData.name + ": " + widgetErrorData.message}}</span>
+  <span [innerHtml]="('Widget Error:<br/><br/>' + widgetErrorData.message) | safe:'html'"></span>
 </div>
 <div class="tb-absolute-fill tb-widget-no-data" *ngIf="displayNoData">
   <span fxLayoutAlign="center center"
diff --git a/ui-ngx/src/app/modules/home/pages/widget/widget-editor.component.ts b/ui-ngx/src/app/modules/home/pages/widget/widget-editor.component.ts
index b12a0dfa3a..0379c34620 100644
--- a/ui-ngx/src/app/modules/home/pages/widget/widget-editor.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/widget/widget-editor.component.ts
@@ -489,9 +489,6 @@ export class WidgetEditorComponent extends PageComponent implements OnInit, OnDe
     if (!this.gotError) {
       this.gotError = true;
       let errorInfo = 'Error:';
-      if (details.name) {
-        errorInfo += ' ' + details.name + ':';
-      }
       if (details.message) {
         errorInfo += ' ' + details.message;
       }
diff --git a/ui-ngx/src/app/shared/components/dialog/alert-dialog.component.html b/ui-ngx/src/app/shared/components/dialog/alert-dialog.component.html
index c3c4b59871..de56079efd 100644
--- a/ui-ngx/src/app/shared/components/dialog/alert-dialog.component.html
+++ b/ui-ngx/src/app/shared/components/dialog/alert-dialog.component.html
@@ -16,7 +16,7 @@
 
 -->
 <h2 mat-dialog-title>{{data.title}}</h2>
-<div mat-dialog-content [innerHTML]="data.message"></div>
+<div mat-dialog-content [innerHTML]="data.message | safe:'html'"></div>
 <div mat-dialog-actions fxLayoutAlign="end center">
   <button mat-button color="primary" [mat-dialog-close]="true" cdkFocusInitial>{{data.ok}}</button>
 </div>
diff --git a/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.html b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.html
new file mode 100644
index 0000000000..8554a3d707
--- /dev/null
+++ b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.html
@@ -0,0 +1,30 @@
+<!--
+
+    Copyright © 2016-2023 The Thingsboard Authors
+
+    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.
+
+-->
+<h2 mat-dialog-title>{{title}}</h2>
+<div mat-dialog-content class="tb-error-alert-dialog-content">
+  <div>{{ message }}</div>
+  <div class="error-message-title" translate>dialog.error-message-title</div>
+  <div class="error-message-content"> {{ errorMessage }} </div>
+  <mat-expansion-panel *ngIf="errorDetails">
+    <mat-expansion-panel-header>{{ 'dialog.error-details-title' | translate }}</mat-expansion-panel-header>
+    <small class="error-details-content" [innerHTML]="errorDetails"></small>
+  </mat-expansion-panel>
+</div>
+<div mat-dialog-actions fxLayoutAlign="end center">
+  <button mat-button color="primary" [mat-dialog-close]="true" cdkFocusInitial>{{data.ok}}</button>
+</div>
diff --git a/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.scss b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.scss
new file mode 100644
index 0000000000..3ca391dbcd
--- /dev/null
+++ b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.scss
@@ -0,0 +1,37 @@
+/**
+ * Copyright © 2016-2023 The Thingsboard Authors
+ *
+ * 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.
+ */
+:host {
+  .mat-mdc-dialog-content {
+    padding: 0 24px 24px;
+  }
+  .tb-error-alert-dialog-content {
+    .error-message-title {
+      font-style: italic;
+    }
+    .error-message-content {
+      color: red;
+    }
+    .error-details-content {
+      display: block;
+      border: solid 1px #d3d3d3;
+      padding: 8px;
+      border-radius: 4px;
+    }
+    & > *:not(:last-child) {
+      padding-bottom: 16px;
+    }
+  }
+}
diff --git a/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.ts b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.ts
new file mode 100644
index 0000000000..8ef9032421
--- /dev/null
+++ b/ui-ngx/src/app/shared/components/dialog/error-alert-dialog.component.ts
@@ -0,0 +1,49 @@
+///
+/// Copyright © 2016-2023 The Thingsboard Authors
+///
+/// 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.
+///
+
+import { Component, Inject } from '@angular/core';
+import { MAT_DIALOG_DATA, MatDialogRef } from '@angular/material/dialog';
+
+export interface ErrorAlertDialogData {
+  title: string;
+  message: string;
+  error: any;
+  ok: string;
+}
+
+@Component({
+  selector: 'tb-error-alert-dialog',
+  templateUrl: './error-alert-dialog.component.html',
+  styleUrls: ['./error-alert-dialog.component.scss']
+})
+export class ErrorAlertDialogComponent {
+
+  title: string;
+  message: string;
+  errorMessage: string;
+  errorDetails?: string;
+
+  constructor(public dialogRef: MatDialogRef<ErrorAlertDialogComponent>,
+              @Inject(MAT_DIALOG_DATA) public data: ErrorAlertDialogData) {
+    this.title = this.data.title;
+    this.message = this.data.message;
+    this.errorMessage = this.data.error.message ? this.data.error.message : JSON.stringify(this.data.error);
+    if (this.data.error.stack) {
+      this.errorDetails = this.data.error.stack.replaceAll('\n', '<br/>');
+    }
+  }
+
+}
diff --git a/ui-ngx/src/app/shared/components/snack-bar-component.scss b/ui-ngx/src/app/shared/components/snack-bar-component.scss
index 8832604510..b2db177e06 100644
--- a/ui-ngx/src/app/shared/components/snack-bar-component.scss
+++ b/ui-ngx/src/app/shared/components/snack-bar-component.scss
@@ -51,7 +51,7 @@
     padding: 0 18px;
     margin: 8px;
     .toast-text {
-      padding: 0 6px;
+      padding: 8px;
       width: 100%;
     }
     button {
diff --git a/ui-ngx/src/app/shared/shared.module.ts b/ui-ngx/src/app/shared/shared.module.ts
index 9bd9006399..60877bd20d 100644
--- a/ui-ngx/src/app/shared/shared.module.ts
+++ b/ui-ngx/src/app/shared/shared.module.ts
@@ -123,6 +123,7 @@ import { JsFuncComponent } from '@shared/components/js-func.component';
 import { JsonFormComponent } from '@shared/components/json-form/json-form.component';
 import { ConfirmDialogComponent } from '@shared/components/dialog/confirm-dialog.component';
 import { AlertDialogComponent } from '@shared/components/dialog/alert-dialog.component';
+import { ErrorAlertDialogComponent } from '@shared/components/dialog/error-alert-dialog.component';
 import { TodoDialogComponent } from '@shared/components/dialog/todo-dialog.component';
 import { MaterialIconsDialogComponent } from '@shared/components/dialog/material-icons-dialog.component';
 import { MaterialIconSelectComponent } from '@shared/components/material-icon-select.component';
@@ -305,6 +306,7 @@ export function MarkedOptionsFactory(markedOptionsService: MarkedOptionsService)
     WidgetsBundleSelectComponent,
     ConfirmDialogComponent,
     AlertDialogComponent,
+    ErrorAlertDialogComponent,
     TodoDialogComponent,
     ColorPickerDialogComponent,
     MaterialIconsDialogComponent,
@@ -528,6 +530,7 @@ export function MarkedOptionsFactory(markedOptionsService: MarkedOptionsService)
     MarkdownModule,
     ConfirmDialogComponent,
     AlertDialogComponent,
+    ErrorAlertDialogComponent,
     TodoDialogComponent,
     ColorPickerDialogComponent,
     MaterialIconsDialogComponent,
diff --git a/ui-ngx/src/assets/locale/locale.constant-en_US.json b/ui-ngx/src/assets/locale/locale.constant-en_US.json
index bcaa4a183f..c9d236bf2a 100644
--- a/ui-ngx/src/assets/locale/locale.constant-en_US.json
+++ b/ui-ngx/src/assets/locale/locale.constant-en_US.json
@@ -1789,7 +1789,9 @@
         }
     },
     "dialog": {
-        "close": "Close dialog"
+        "close": "Close dialog",
+        "error-message-title": "Error message:",
+        "error-details-title": "Error details"
     },
     "direction": {
         "column": "Column",
@@ -3991,7 +3993,8 @@
         "alarm-data-overflow": "Widget displays alarms for {{allowedEntities}} (maximum allowed) entities out of {{totalEntities}} entities",
         "search": "Search widget",
         "filter": "Widget filter type",
-        "loading-widgets": "Loading widgets..."
+        "loading-widgets": "Loading widgets...",
+        "widget-template-error": "Invalid widget HTML template."
     },
     "widget-action": {
         "header-button": "Widget header button",
@@ -4000,6 +4003,9 @@
         "open-dashboard": "Navigate to other dashboard",
         "custom": "Custom action",
         "custom-pretty": "Custom action (with HTML template)",
+        "custom-pretty-error-title": "Custom dialog error",
+        "custom-pretty-template-error": "Invalid custom dialog template.",
+        "custom-pretty-controller-error": "Error occurred while evaluating custom dialog function.",
         "mobile-action": "Mobile action",
         "target-dashboard-state": "Target dashboard state",
         "target-dashboard-state-required": "Target dashboard state is required",