Log size limit reached! No further messages will be logged.

What causes this issue?

The maximum level for logging messages is reached.

System Response

The system will stop logging further messages to allow saving of the
application log.

How to fix this error?

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

Procedure for System Administrators

A single application log allows a maximum of 999999 messages to be
saved. In case the system would try to save more messages an error would
occur and no messages will be saved.

Error message extract from SAP system. Copyright SAP SE.