What causes this issue?

A program error occurred while the system was writing changes to the
database.

System Response

All changes related to SAP LUW are discarded.

How to fix this error?

Note the relevant information, such as transaction, policy or contract
number, and processing steps.
Contact your IT department or SAP Support.

Procedure for System Administrators

For more information about the error, view the system log (transaction
code <AB>SM21</>) and the monitor for update requests (transaction code
<AB>SM13</>).

Error message extract from SAP system. Copyright SAP SE.