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

If it helps anyone,  I'm having the same issues with Excel.

UPDATE:  There was a patch for Office today but it did not fix the problem for me (Office 2016, not 365)

I have been checking for updates to Office 2016 daily during this problem.  There were patches to Office today and I applied them.  I then opened a Word doc on OneDrive, made a change, clicked File then Save and I got the same popup.  I was able to close (X), and save the file as normal.  The pop-up has not gone away for my config.

Just in case:  How to manually apply updates

Open an office app (e.g., Word) and create a new blank document (so you don't mess up a real doc).  Click on File, then Account, then Update Options (button toward the middle of the screen), select Update Now.  You will get a window showing update status.  Note:  If there are updates, you will have to close all Office Apps so be ready (including Outlook).  This works for Office 2016 - someone with 365 can verify for that config.

No good results but wanted to let you know.

sf

Same issue here, except this time it happened to me with PowerPoint and I was unable to log in or close the message. The program was frozen. I had to shut down PowerPoint using the task manager and lost about 30 minutes of work despite having saved numerous times. Definitely a One Drive issue.