Please raise a support ticket while I try to find some hints about what's causing this.
My first guess would have been that you are using a wrong client but since you mentioned you tried several... I assume you upgrade not only the client but the server as well?
If this is coming from a version of Windows from May, it may have been tested only this summer (whereas the current latest Campaign build is from March), so we may probably have fixes coming in the next build of Adobe Campaign (which is next month or so).
Let me know if you manage to get this resolved somehow, I'll follow up on this issue with the product team.