& keys of object & were deleted

What causes this issue?

The header entry was deleted from an object, although it still had
keys.
<ZH>Cause:</>
The line was deleted.
The line was overwritten.

System Response

The key entries were deleted.

How to fix this error?

If you did not want to delete the header, select <LS>Reset</> in the
menu.
This restores the status that was last saved.

Error message extract from SAP system. Copyright SAP SE.