Hi Ulrich,
It looks like there is a missing assembly in your output directory - the one called ExcelDna.Registration.VisualBasic.dll.
I'm guessing this file is in the build output that you are debugging, but not part of the add-in you are deploying.
The related assembly just called ExcelDna.Registration.dll might give you the same problem after this one is sorted out, or might already be set up correctly.
If you are making a single-file packed add-in, you'll also need to add some entries to your project .dna file that look like:
<Reference Path="ExcelDna.Registration.dll" Pack="true" />
<Reference Path="ExcelDna.Registration.VisualBasic.dll" Pack="true" />
-Govert
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