NgTemplateOutlet: cannot assign a link or variable

Question

When using ngTemplateOutlet and context:

<ng-container *ngTemplateOutlet="template; context: Context"></ng-container> 

Context Data:

 this.Context = { $implicit: this.userName, 'password': this.password, 'Login': this.Login, 'Register': this.Register }; 

can't be attached to a binding in two ways, is this a limitation or am I doing something wrong?

 <ng-template let-username #loginpage> <TextField class="input" hint="Email" keyboardType="email" [(ngModel)]="username"></TextField> </ng-template> 

I get this error:

ns-renderer: Unable to assign a link or variable!