When I was hit with this error. All I had to do was, run; 'ng update'. I was given the suggestion what to do next. Attached for reference below;
In my case I had to run as suggested; 'ng update @angular/core@12'
✖ Migration failed: Could not find any tsconfig file. Cannot migrate AbstractControl.parent accesses.
  See "/private/var/folders/s/C/K/angular-errors.log" for further details.
    app_code % ng update
    Using package manager: 'npm'
    Collecting installed dependencies...
    Found 29 dependencies.
        We analyzed your package.json, there are some packages to update:
        
          Name                               Version                  Command to update
         --------------------------------------------------------------------------------
          @angular/core                      11.2.14 -> 12.2.9        **ng update @angular/core@12**