complete upgrade to angular

src/app/file-explorer/file-explorer.component.ts

@@ -14,8 +14,7 @@ import { RenameDialogComponent } from './modals/renameDialog/renameDialog.compon
 export class FileExplorerComponent {
   constructor(public dialog: MatDialog) {}
 
-  @ViewChild(MatMenuTrigger)
-  contextMenu: MatMenuTrigger;
+    @ViewChild(MatMenuTrigger, {static: false }) contextMenu: MatMenuTrigger;
 
   contextMenuPosition = { x: '0px', y: '0px' };
 

src/app/launch-dialog/launch-dialog.component.ts

@@ -17,8 +17,7 @@ export class LaunchDialogComponent implements OnInit {
   batchcmdsafeurl: any;
   appconfigsafeurl: any;
   rmListen: any;
-  @ViewChild('launchbtn', { read: ElementRef })
-  launchbtn: ElementRef;
+  @ViewChild('launchbtn', { read: ElementRef, static: false }) launchbtn: ElementRef;
   setFocus: Boolean;
   sub: Subscription;
 

src/polyfills.ts

@@ -43,7 +43,7 @@
 
 /** Evergreen browsers require these. **/
 // Used for reflect-metadata in JIT. If you use AOT (and only Angular decorators), you can remove.
-import 'core-js/es7/reflect';
+//import 'core-js/es7/reflect';
 
 
 /**