The error is reported when you edit the method configuration and user-defined elements selected there are no longer available.
Error message
The configuration of the project <Project name> contains unknown user-defined model or symbol types. Default types will automatically be used for these types.
Cause
A database with SAPĀ® projects, whose method configuration contains user-defined method elements, has been restored on an >_abs< that does not contain these method elements. However, these elements are not used in the projects of the restored database. In this case, these method elements are not made available for the tenant. Only elements used in projects are created.
The user-defined method elements have been deleted from the tenant.
Solution
If the missing user-defined method elements still exist in the configuration of another tenant, create a database there in which these elements are used. Save the database and restore it on the tenant in whose configuration the elements are missing. The missing method elements are created automatically.
Recreate the user-defined elements.