Try a sledgehammer
<div [class.form-group]="formGroupClass"
[class.has-error]="showErrorMessages"
[formGroup]="group"
- [hidden]="model && model.inputType === 'hidden'"
+ [hidden]="model && model['inputType'] === 'hidden'"
[ngClass]="[elementContainerClass, gridContainerClass]">
<label *ngIf="type !== 2 && model.label !== null"
