We are using BPC 7 on Microsoft. We have one user that is having trouble accessing BPC, we'll call her J. Everything used to work fine for her. Recently it stopped working. She is still in the appropriate network security groups. Here is what happens now.
Whenever J is logged in to a computer, you cannot connect to BPC in the wizard using any account. The error is "The system cannot connect to the (HTTP://Server) Application server. Verify that you have specified a valid Application server name, or see if the Application server is unavailable at this time." However, when you log in to the same computer as a different user, you can then connect to BPC in the wizard using J's account or anyone else's. We have replicated this on multiple computers.
I don't think it's a server issue because everyone else works. I don't think it's a computer issue because you can log on as someone else and it works. I don't think it's a desktop profile issue, because it happens on multiple computers. I don't think it's a BPC account issue, because if you log on to the computer as someone else, you can then connect to BPC using her account. That just leaves the network account, but I am not sure what to check.