If possible, I would recommend that you rather use the Open API File Geodatabase writer, it’s both faster and doesn’t require any Esri/ArcGIS libraries.

There are some limitations, but as long as you write only points, lines and polygons, this probably won’t matter. See also https://docs.safe.com/fme/html/FME-Form-Documentation/FME-ReadersWriters/filegdb/Geometry-Support-filegdb.htm

Otherwise, have a look at the troubleshooting guide for FME and ArcGIS issues: https://support.safe.com/hc/en-us/articles/25407556603149-FME-and-Esri-ArcGIS-Troubleshooting-Guide

You could also force to not read from or write to the same database simultaneous. Or write to the same database with multiple writers simultaneous.

This could fix problems with locks on your databases. And don’t forget to close any other programs locking your database.

But it could also be other causes.

Thank you for your support. I still think it's a memory problem. As I wrote, If I deactivate a few readers (dgns), the run is completed without errors. But I have found another solution so that the workbench runs with all readers. The workbench also creates some analysis files in Excel format. If I deactivate these transformers, the run is also completed without errors. I think that when running with all readers, too many entries are created in the analysis files, which leads to a kind of memory overflow. Perhaps the maximum number of entries to be expected can be increased somewhere?