Operation not allowed in display mode

What causes this issue?

You wanted to change or save but the cursor is in the wrong window of
the editor.

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?

Position the cursor in the editor window in which you changed the
program.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.