diff --git a/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.html b/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.html
index a3da1fbe..b9a429b1 100644
--- a/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.html
+++ b/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.html
@@ -46,10 +46,11 @@ <h4 class="strong d-flex mb-2">
             [readonly]="true"
             [formControl]="fileName"
             (click)="selectFile()"
+            [errorStateMatcher]="fileUploadErrorStateMatcher"
             required />
           <mat-error
             *ngIf="
-              fileName.errors?.required && (fileName.touched || fileName.dirty) && !validatingUpload
+              fileName.errors?.required && fileName.touched && fileName.dirty && !validatingUpload
             ">
             {{ (messages$ | async)?.formFileRequired || 'File is required' }}
           </mat-error>
@@ -62,6 +63,7 @@ <h4 class="strong d-flex mb-2">
           <mat-error *ngIf="fileName.errors?.requestFormat && (fileName.touched || fileName.dirty)">
             {{ (messages$ | async)?.formInvalidRequestFormat || 'Invalid request format' }}
           </mat-error>
+          <mat-hint>.json or .zip</mat-hint>
         </mat-form-field>
         <button
           type="button"
@@ -110,6 +112,7 @@ <h4 class="strong d-flex mb-2">
           #fileInput
           type="file"
           accept=".json,.zip"
+          (cancel)="onCancelSelectFile()"
           (click)="fileUploadClicked($event)"
           (change)="fileSelected($event)" />
       </div>
diff --git a/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.ts b/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.ts
index 47deade7..2cb8b878 100644
--- a/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.ts
+++ b/application/frontend/src/app/core/containers/upload-dialog/upload-dialog.component.ts
@@ -9,6 +9,8 @@
 
 import { ChangeDetectionStrategy, Component, ElementRef, ViewChild } from '@angular/core';
 import {
+  FormGroupDirective,
+  NgForm,
   UntypedFormBuilder,
   UntypedFormControl,
   UntypedFormGroup,
@@ -29,6 +31,23 @@ import { toDispatcherLatLng } from 'src/app/util';
 import { ScenarioSolutionHelpDialogComponent } from 'src/app/core/containers/scenario-solution-help-dialog/scenario-solution-help-dialog.component';
 import { UploadActions } from '../../actions';
 import { CsvHelpDialogComponent } from '../csv-help-dialog/csv-help-dialog.component';
+import { ErrorStateMatcher } from '@angular/material/core';
+
+class FileUploadErrorStateMatcher implements ErrorStateMatcher {
+  isErrorState(
+    control: UntypedFormControl | null,
+    ngForm: FormGroupDirective | NgForm | null
+  ): boolean {
+    const invalid =
+      ngForm?.errors?.required ||
+      ngForm.errors?.zipContents ||
+      ngForm.errors?.fileFormat ||
+      ngForm.errors?.requestFormat ||
+      control?.invalid;
+    const show = ngForm?.touched && ngForm?.dirty;
+    return !!(invalid && show);
+  }
+}
 
 @Component({
   selector: 'app-upload-dialog',
@@ -39,6 +58,7 @@ import { CsvHelpDialogComponent } from '../csv-help-dialog/csv-help-dialog.compo
 export class UploadDialogComponent {
   @ViewChild('fileInput', { static: true }) fileInput: ElementRef<HTMLInputElement>;
 
+  readonly fileUploadErrorStateMatcher = new FileUploadErrorStateMatcher();
   readonly form: UntypedFormGroup;
   readonly fileName: UntypedFormControl;
   fileInvalid: boolean;
@@ -111,7 +131,6 @@ export class UploadDialogComponent {
     if (!this.fileInput) {
       return;
     }
-
     this.fileInput.nativeElement.click();
     this.fileName.markAsTouched();
   }
@@ -120,7 +139,12 @@ export class UploadDialogComponent {
     (e.target as HTMLInputElement).value = null;
   }
 
+  onCancelSelectFile(): void {
+    this.fileName.markAsDirty();
+  }
+
   async fileSelected(e: Event): Promise<void> {
+    this.fileName.markAsDirty();
     const target = e.target as HTMLInputElement;
     const file = target && target.files && target.files[0];
     if (!file) {