Internal error: Unable to check syntax of include &

What causes this issue?

Unable to perform the syntax check.
Possible causes: The main program of the include to be checked could
not be found or does not correspond to the include.

System Response

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

How to fix this error?

Procedure for System Administrators

Inform your system administrator.

Error message extract from SAP system. Copyright SAP SE.