angular: is not a known element

 

>PROBLEM

An element is not recognized, returning the following error message:

angular: is not a known element

>SOLUTION

A referencing error may lead to side effects during parsing operation.

The issue is caused by a missing reference that becomes invalid.
It is example happened because the component was deleted using the editor, but it was not able to remove the respective reference together.
It may happen also when you rename or move componets.

Removing the missing references:

the problem is gone.

NOTE:

Errors of @NgModule may lead also to another errors, for instance like NG8002.

>CHECK

angular: ngForm: error NG8002: Can't bind to 'formControl' since it isn't a known property of 'input'.

angular or another framework/language: Mysterious compilation errors suddenly appeared after restarting app

>MODULE/SUB-MODULE CONFIG BY IMAGES

Follow by the images how to set up the imports using module and sub-modules through images.

>ENV

Angular CLI: 13.2.2
Node: 16.13.1
Package Manager: npm 8.5.4
OS: win32 x64