Activity &1 could not be updated (->long text)

What causes this issue?

An error occurred when deleting a long text
Target version : &V1&
Fiscal year : &V2&
Object number : &V3&
Cost element : &V4&

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?

Error message extract from SAP system. Copyright SAP SE.