[解決済み] エラーです。参照または変数に代入できません! Angular 4 [重複]の場合

質問

angular4で新しいhtmlコードを追加した後、エラーが発生します。私は新しいコードをコメントしようとしましたが、まだ動作していません。

私のコード

<form role="form" #adminForm="ngForm" (ngSubmit)="logAdmin(adminForm.form)">
          <div class="form-group">
            <input class="form-control" [(ngModel)]="adminUsername" #adminUsername="ngModel" placeholder="Username" type="text" name="adminUsername"
              required>
            <div *ngIf="adminUsername.touched && adminUsername.errors">
              <div class="alert alert-danger" *ngIf="adminUsername.errors.required">Username is required</div>
            </div>
          </div>
          <div class="form-group">
            <input class="form-control" [(ngModel)]="passwordText" #adminPassword="ngModel" id="adminPassword" name="adminPassword" placeholder="Password"
              type="password" required>
          </div>
          <div class="alert alert-danger" *ngIf="adminPassword.touched && adminPassword.errors">Password is required</div>
          <div class="col-md-6" style="text-align: right">
            <button type="submit" class="btn-yellow" [disabled]="!adminForm.valid">Log In</button>
          </div>
        </form>

私が得ているエラー:

Error: Cannot assign to a reference or variable!
    at _AstToIrVisitor.visitPropertyWrite (webpack-internal:///../../../compiler/esm5/compiler.js:26550:23)
    at PropertyWrite.visit (webpack-internal:///../../../compiler/esm5/compiler.js:4895:24)
    at convertActionBinding (webpack-internal:///../../../compiler/esm5/compiler.js:26000:45)
    at eval (webpack-internal:///../../../compiler/esm5/compiler.js:28519:22)
    at Array.forEach (<anonymous>)
    at ViewBuilder._createElementHandleEventFn (webpack-internal:///../../../compiler/esm5/compiler.js:28515:18)
    at nodes.(anonymous function) (webpack-internal:///../../../compiler/esm5/compiler.js:27934:27)
    at eval (webpack-internal:///../../../compiler/esm5/compiler.js:28460:22)
    at Array.map (<anonymous>)
    at ViewBuilder._createNodeExpressions (webpack-internal:///../../../compiler/esm5/compiler.js:28459:56)
    at _AstToIrVisitor.visitPropertyWrite (webpack-internal:///../../../compiler/esm5/compiler.js:26550:23)
    at PropertyWrite.visit (webpack-internal:///../../../compiler/esm5/compiler.js:4895:24)
    at convertActionBinding (webpack-internal:///../../../compiler/esm5/compiler.js:26000:45)
    at eval (webpack-internal:///../../../compiler/esm5/compiler.js:28519:22)
    at Array.forEach (<anonymous>)
    at ViewBuilder._createElementHandleEventFn (webpack-internal:///../../../compiler/esm5/compiler.js:28515:18)
    at nodes.(anonymous function) (webpack-internal:///../../../compiler/esm5/compiler.js:27934:27)
    at eval (webpack-internal:///../../../compiler/esm5/compiler.js:28460:22)
    at Array.map (<anonymous>)
    at ViewBuilder._createNodeExpressions (webpack-internal:///../../../compiler/esm5/compiler.js:28459:56)
    at resolvePromise (webpack-internal:///../../../../zone.js/dist/zone.js:824:31)
    at resolvePromise (webpack-internal:///../../../../zone.js/dist/zone.js:795:17)
    at eval (webpack-internal:///../../../../zone.js/dist/zone.js:873:17)
    at ZoneDelegate.invokeTask (webpack-internal:///../../../../zone.js/dist/zone.js:425:31)
    at Object.onInvokeTask (webpack-internal:///../../../core/esm5/core.js:4944:33)
    at ZoneDelegate.invokeTask (webpack-internal:///../../../../zone.js/dist/zone.js:424:36)
    at Zone.runTask (webpack-internal:///../../../../zone.js/dist/zone.js:192:47)
    at drainMicroTaskQueue (webpack-internal:///../../../../zone.js/dist/zone.js:602:35)
    at <anonymous>

インターネットで検索してみると、同じエラーに関する質問と回答が見つかりました。そのため、このエラーは繰り返されるかもしれませんが、その答えは多くの場合、異なるようです。

解決方法は？

問題は、ngModelの変数名を全く同じに変更したことです。

[(ngModel)]="adminUsername" #adminUsername="ngModel" 

私の場合、解決策は

[(ngModel)]="adminUsernameText" #adminUsername="ngModel"