Angular can't find a directive with {{ PLACEHOLDER }} export name.
This is common with a missing import or a missing exportAs on a directive.
HELPFUL: This is the compiler equivalent of a common runtime error NG0301: Export Not Found.
Debugging the error
Use the string name of the export not found to trace the templates or modules using this export.
Ensure that all dependencies are properly imported and declared in our Modules.
For example, if the export not found is ngForm, we will need to import FormsModule and declare it in our list of imports in *.module.ts to resolve the missing export error.
import { FormsModule } from '@angular/forms';@NgModule({ … imports: [ FormsModule, …
If you recently added an import, you will need to restart your server to see these changes.