Thanks for all the tips so far. I may have found the solution. As Arnie said:
- Close all running OneDrive and Sharepoint processes. I did this from TaskManager because although I can see OneDrive and quit it from toolbar, I can only quit SharePoint in TM
- Go to C:\Users\PROFILENAME\AppData\Local\Microsoft\OneDrive\settings
- There should be folders named Business and Personal. Business will have a digit at the end. Delete the BusinessX folder that corresponds to the workplace account you've signed out of/disconnected from your PC (for me this was Business1 and I kept Business2 which is a current workplace MS account)
Then:
- Also go to C:\Users\PROFILENAME\AppData\Local\Microsoft\OneDrive\ListSync **** and delete the BusinessX account folder there too (again Business1 for me, depends for you...)
- Restart computer which will restart OneDrive for both personal and business drives.
Fingers crossed -- and this has worked for me with two restarts to test.
I guess it was the ListSync folder that contained the commands that set off the notification?
I followed the steps above and they did not work for me, but I banged around a bunch and finally got the prompt to go away. Here are the things I did, and my thoughts on what finally fixed it.
- Follow steps 1-4 of @JonRHerring's instructions above. At this point, your OneDrive and SharePoint processes should be stopped.
- Go into C:\Users\PROFILENAME\AppData\Local\Microsoft\OneAuth\accounts
- Find the account ID for the business account that keeps syncing. For me, there were two files in there. One was for my personal account and one had information for my long-deleted (over 1 year) business account. They are JSON files, so you can open and read them. Save this ID and the login of the account found within the JSON file.
- Delete the file in C:\Users\PROFILENAME\AppData\Local\Microsoft\OneAuth\accounts for the business account
- Delete any files in C:\Users\PROFILENAME\AppData\Local\Microsoft\OneAuth\blobs with filenames containing the business account ID you saved (the files will have the ID in the name, but will also have other characters in the filename as well).
- Delete any files and folders under C:\Users\PROFILENAME\AppData\Local\Microsoft\Office that contain the business account ID in the file or folder name. Some of the locations in which these files appear include Office\16.0\aggmru, Office\16.0\MruServiceCache, and Office\16.0\TapCache. There may be others, though. I did not keep an exhaustive list.
- Delete any files and folders under C:\Users\PROFILENAME\AppData\Local\Microsoft\Office that contain the login of the business account in the file or folder name. One such location is Office\16.0\BackstageInAppNavCache.
- From the Start Menu, search for "Services" and run the Services app. Stop the "Connected Devices Platform Service" service.
- Delete any files and folders under C:\Users\PROFILENAME\AppData\Local\ConnectedDevicesPlatform that contain the business account ID in the file or folder name.
- Edit C:\Users\PROFILENAME\AppData\Local\ConnectedDevicesPlatform\CDPGlobalSettings.cdp with Notepad or some simple text editor (I used VS Code). Find the JSON key for "ActivityStoreInfo" and remove the object with a "stableUserId" matching the business account ID. The object is all of the text including and between the curly braces ("{ ... }"). If there is only one other object within that section, make sure there is no comma after the object's curly brace. Save the file.
- Delete any registry keys referencing the business account ID. I did not have any left after previous searches and removals of my business account login, but if you have not done that yet, you may need to do it.
- Restart the computer.
After doing all of this, I no longer get the prompt, where I reliably got it within a few hours of restart.
I am reasonably certain that the cleaning out of the account information from the Microsoft Office folders is what ended the prompt for me. I did the Connected Devices cleanup later after a more thorough search of the system for references to my business account.
What I find interesting is that even after going through this, a few hours after restarting OneDrive, the ListSync\Business1 folder will be recreated, but SharePoint is not running on the system and I never get the prompt. I think SharePoint may start up, create that folder, not find any business account references within Office, and then exit.
Regardless, for me, the prompt no longer appears.