Hi Erwin and welcome to the forum.
From memory the postings and the knowledge base and main Datawatch site support FAQs that relate to the dll error message include some suggestions that the problem could be to do with permissions. The connection with permissions and IT stuff having been recently 'moved' in some way or another is usually quite strong.
So I am assuming that you and your IT people have already checked that possibility thoroughly.
I'm guessing you are using a networked version of Monarch? (If it is a local version you should be able to find the MFWFIL32.DLL file on your machine.)
Sorry I can't offer a more helpful suggesiton.