Hello Daniel,
sorry for my late reply. I investigated the behaviour a bit more.
First I tried to use the built-in digisign.exe, but this tool seems to be very, very ..... slow, or there is another problem(?).
Then I checked AI calls to signtool.exe from Windows SDK with procmon. I saw that AI is generating files with generated names for all dlls to be digitally signed in %appdata%\local\temp in the profile of the domain user running Jenkins service.
I had a look at the directory, there were lots of files with these generated names. I deleted all the files and now it seems AI is working again without problems.
We will watch and give you feedback again.
Thanks and best regards,
Bernd