Thanks for your input! I did what you recommended, here are the results.
They opened wyUpdate with taskmanager on the side, but did not notice any process opening.
We shipped version 2.6.18.4, original produced by wyBuild.
They sent me a screenshot with the digital signing information. Everything looks fine.
Additionally to your suggestions, I did come up with the following:- Run as Administartor -> no effect- Windows version: 7 Prof. 32bit, english language with some polnisch culture settings (e.g. date format)- What .NET versions are installed? Answer: Only .NET 4.5. Our other customers (it works everywhere else) have .NET 4.0 Client Profile, so this is an interesting find. However, I could not reproduce it on my test VM when I installed 4.5 there. I told them to downgrade anyways, so we will see.
I'm waiting for the response to .NET downgrade now. Also, I gave them a batch file to check the return code of wyUpdate.
Do you have any further suggestions in the meantime?