diff --git a/projects/player/src/app/components/elements/compound-group-element/compound-group-element.component.ts b/projects/player/src/app/components/elements/compound-group-element/compound-group-element.component.ts
index 536880f5f0dc3a443cdf49f31881a217c752f4fd..431983efd914adea6196ec2835bde691916bb902 100644
--- a/projects/player/src/app/components/elements/compound-group-element/compound-group-element.component.ts
+++ b/projects/player/src/app/components/elements/compound-group-element/compound-group-element.component.ts
@@ -1,22 +1,22 @@
 import { Component, OnInit, ViewChild } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
 import { takeUntil } from 'rxjs/operators';
-import { UnitStateService } from '../../../services/unit-state.service';
 import { ElementComponent } from 'common/directives/element-component.directive';
-import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
 import { MessageService } from 'common/services/message.service';
 import { VeronaSubscriptionService } from 'player/modules/verona/services/verona-subscription.service';
-import { ValidationService } from '../../../services/validation.service';
-import { KeypadService } from '../../../services/keypad.service';
-import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
-import { KeyboardService } from '../../../services/keyboard.service';
-import { DeviceService } from '../../../services/device.service';
 import {
   TextFieldSimpleComponent
 } from 'common/components/compound-elements/cloze/cloze-child-elements/text-field-simple.component';
 import { ClozeElement } from 'common/models/elements/compound-elements/cloze/cloze';
 import { LikertElement } from 'common/models/elements/compound-elements/likert/likert';
 import { CompoundElement, InputElement } from 'common/models/elements/element';
+import { UnitStateService } from '../../../services/unit-state.service';
+import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
+import { ValidationService } from '../../../services/validation.service';
+import { KeypadService } from '../../../services/keypad.service';
+import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
+import { KeyboardService } from '../../../services/keyboard.service';
+import { DeviceService } from '../../../services/device.service';
 
 @Component({
   selector: 'aspect-compound-group-element',
@@ -39,7 +39,7 @@ export class CompoundGroupElementComponent extends ElementFormGroupDirective imp
     public translateService: TranslateService,
     public messageService: MessageService,
     public veronaSubscriptionService: VeronaSubscriptionService,
-    public validatorService: ValidationService
+    public validationService: ValidationService
   ) {
     super();
   }
@@ -99,4 +99,3 @@ export class CompoundGroupElementComponent extends ElementFormGroupDirective imp
     this.keyboardService.close();
   }
 }
-
diff --git a/projects/player/src/app/components/elements/input-group-element/input-group-element.component.ts b/projects/player/src/app/components/elements/input-group-element/input-group-element.component.ts
index d3661c1706db5004626081194c80431fb10845e0..c41bd5b0f4cb4d532f7fb1ae7cb4df5cdc6730c3 100644
--- a/projects/player/src/app/components/elements/input-group-element/input-group-element.component.ts
+++ b/projects/player/src/app/components/elements/input-group-element/input-group-element.component.ts
@@ -2,13 +2,9 @@ import {
   AfterViewInit, Component, OnInit, ViewChild
 } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
-import { UnitStateService } from '../../../services/unit-state.service';
-import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
-import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
 import { MessageService } from 'common/services/message.service';
 import { VeronaSubscriptionService } from 'player/modules/verona/services/verona-subscription.service';
 import { ElementComponent } from 'common/directives/element-component.directive';
-import { ValidationService } from '../../../services/validation.service';
 import { CheckboxElement } from 'common/models/elements/input-elements/checkbox';
 import { SliderElement } from 'common/models/elements/input-elements/slider';
 import { DropListElement } from 'common/models/elements/input-elements/drop-list';
@@ -16,6 +12,10 @@ import { RadioButtonGroupElement } from 'common/models/elements/input-elements/r
 import { RadioButtonGroupComplexElement } from 'common/models/elements/input-elements/radio-button-group-complex';
 import { DropdownElement } from 'common/models/elements/input-elements/dropdown';
 import { InputElement } from 'common/models/elements/element';
+import { ValidationService } from '../../../services/validation.service';
+import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
+import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
+import { UnitStateService } from '../../../services/unit-state.service';
 
 @Component({
   selector: 'aspect-input-group-element',
@@ -37,7 +37,7 @@ export class InputGroupElementComponent extends ElementFormGroupDirective implem
     public translateService: TranslateService,
     public messageService: MessageService,
     public veronaSubscriptionService: VeronaSubscriptionService,
-    public validatorService: ValidationService
+    public validationService: ValidationService
   ) {
     super();
   }
diff --git a/projects/player/src/app/components/elements/text-input-group-element/text-input-group-element.component.ts b/projects/player/src/app/components/elements/text-input-group-element/text-input-group-element.component.ts
index 1c2b98ab759aa318d6fdbe90a8b0275e07861e36..8e03ae2f978b5340159a4845b472ef485470d2cd 100644
--- a/projects/player/src/app/components/elements/text-input-group-element/text-input-group-element.component.ts
+++ b/projects/player/src/app/components/elements/text-input-group-element/text-input-group-element.component.ts
@@ -2,23 +2,23 @@ import {
   AfterViewInit, Component, OnInit, ViewChild
 } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
-import { KeypadService } from '../../../services/keypad.service';
-import { UnitStateService } from '../../../services/unit-state.service';
-import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
 import { MessageService } from 'common/services/message.service';
 import { VeronaSubscriptionService } from 'player/modules/verona/services/verona-subscription.service';
 import { ElementComponent } from 'common/directives/element-component.directive';
-import { ValidationService } from '../../../services/validation.service';
-import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
 import { TextAreaComponent } from 'common/components/input-elements/text-area.component';
 import { TextFieldComponent } from 'common/components/input-elements/text-field.component';
-import { KeyboardService } from '../../../services/keyboard.service';
 import { SpellCorrectComponent } from 'common/components/input-elements/spell-correct.component';
-import { DeviceService } from '../../../services/device.service';
 import { TextAreaElement } from 'common/models/elements/input-elements/text-area';
 import { TextFieldElement } from 'common/models/elements/input-elements/text-field';
 import { SpellCorrectElement } from 'common/models/elements/input-elements/spell-correct';
 import { InputElement } from 'common/models/elements/element';
+import { DeviceService } from '../../../services/device.service';
+import { KeyboardService } from '../../../services/keyboard.service';
+import { ElementFormGroupDirective } from '../../../directives/element-form-group.directive';
+import { ValidationService } from '../../../services/validation.service';
+import { ElementModelElementCodeMappingService } from '../../../services/element-model-element-code-mapping.service';
+import { UnitStateService } from '../../../services/unit-state.service';
+import { KeypadService } from '../../../services/keypad.service';
 
 @Component({
   selector: 'aspect-text-input-group-element',
@@ -41,7 +41,7 @@ export class TextInputGroupElementComponent extends ElementFormGroupDirective im
     public translateService: TranslateService,
     public messageService: MessageService,
     public veronaSubscriptionService: VeronaSubscriptionService,
-    public validatorService: ValidationService,
+    public validationService: ValidationService,
     public deviceService: DeviceService
   ) {
     super();
diff --git a/projects/player/src/app/directives/element-form-group.directive.ts b/projects/player/src/app/directives/element-form-group.directive.ts
index 2b1b738d13c8b2e8d4c4de1ed7523a81dd7ab8d2..79f238c7a172dcf8136c5e296ccd1ac14350e871 100644
--- a/projects/player/src/app/directives/element-form-group.directive.ts
+++ b/projects/player/src/app/directives/element-form-group.directive.ts
@@ -24,7 +24,7 @@ export abstract class ElementFormGroupDirective extends ElementGroupDirective im
   abstract translateService: TranslateService;
   abstract messageService: MessageService;
   abstract veronaSubscriptionService: VeronaSubscriptionService;
-  abstract validatorService: ValidationService;
+  abstract validationService: ValidationService;
 
   ngUnsubscribe = new Subject<void>();
 
@@ -43,7 +43,7 @@ export abstract class ElementFormGroupDirective extends ElementGroupDirective im
           });
         });
       if (ElementFormGroupDirective.needsValidation(elementModel)) {
-        this.validatorService.registerFormControl(formControl);
+        this.validationService.registerFormControl(formControl);
       }
     });
     this.veronaSubscriptionService.vopNavigationDeniedNotification