Tell us the account you want to use to open _vti_rpc.

The reply from this thread (also mentioned here) about deleting your cached credentials solved the dialog box problem, but now I have a much worse problem. Now every time I open a document for the first time since the update that introduced the _vti_rpc dialog box, Word hangs and I have to kill the process. Second time I open the doc it's fine, but for someone who works with Word docs all day long, this has crippled my productivity.

So consider how annoying it is to X out of the authentication prompt (which is harmless) vs. how annoying it would be to have Word hang every time you open a doc for the first time. If you mostly work with the same docs over and over, it might be worth doing the above solution.

How can you go back to the previous version of Office?

I'm on build 1607 and still getting this problem.  It only affects Word and Excel.

Its been happening now for at least 5-6 weeks.

I also get it on PowerPoint.

With Word and Excel, I can "X" out of the dialog and move on.

With PowerPoint, it just freezes and I have to kill the whole process in Task Manager :(:(:(

Now, after the office applications installed the latest vetsion: 1710 (build 8613:1000) in fast ring and used applications for a whole week, I found this issue hasn’t occured any more.

The Windows version is currently using the insider version, 16296 in slow ring, but OneDrive has updated into the 2017 version. I think it may solve the problem.