Dynpro & could not be activated.

What causes this issue?

Screen &V1& has been modified for view cluster maintenance and saved.
Screen activation errors occurred, which could not be handled by the
tool.

System Response

The modified screen exists in an inactive state. When you call view
cluster maintenance, the last active version of the screen, which does
not contain the modifications, is called.

How to fix this error?

Activate screen &V1& manually in the Screen Painter. Resolve the errors
reported, so that the screen can be activated successfully.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.