Log cannot be saved: Object/subobject not specified

What causes this issue?

Log save cancelled because at least one log contains no object or
subobject.
Object and subobject are needed to classify application logs because
there are several log types. Only a few logs are managed in main memory
at runtime, so this classification is not needed.
If the logs are to be saved in the database, object/subobject must be
specified for later retrieval.

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?

Procedure for System Administrators

Object/subobject can be passed when a log is created (function module
BAL_LOG_CREATE) and changed with BAL_LOG_CHANGE.
The possible values for object and subobject must be configured in
transaction <DS:TRAN.SLG0>SLG0</>.

Error message extract from SAP system. Copyright SAP SE.