If you have purchased a new computer any time in the past couple of years at least, there's a good chance that during set up you were prompted to login to OneDrive and then suddenly everything on your computer is syncing to OneDrive. That's supposed to be a good thing, right?
I have my personal opinions about having important files backup in OneDrive. I don't do it. (See my recommendations on iDrive on the Recommendations page. It works a lot like OneDrive, but the bots at iDrive aren't crawling my files to look for ways to advertise to me. That gives me a lot more confidence.)
But more than that, Historian does not work well with the way OneDrive continuously looks for updates. You are asking for trouble if you have your Cabinet/Vault syncing to OneDrive. I used to do that a long time ago, but I 100% don't recommend it.
The trouble is, OneDrive does not make it easy to stop it from syncing everything once you have that ball rolling.
Here is the easiest way I have found to stop OneDrive from syncing files.
Click on the little white cloud icon on the bottom right of your screen.
From the pop up window, click on the little gear icon. Select Settings.
In the window that pops up, select Sync and backup and then Manage backup.
A list of your main folders/libraries will come up, but you'll notice at first that the toggle buttons are grayed out and each says “Scanning…” It is mapping out how many files are in each space and you just have to wait for a minute or two for it to complete. Be patient.
Once it completes that mapping, you will see a few of those toggle buttons as blue. Slide them to the left one at a time to stop syncing. By default, usually Documents, Pictures and Desktop are toggled on. You'll have to slide the toggle for one library and wait for it to process before you can toggle the next one. Again, just be patient. It's worth it!
And that's really it! It may take quite a while to stop the syncing for larger folders. For instance, it took over an hour to stop syncing a folder with 106 Gb of files. Just give it time. This is something you want to do when you can start the process and walk away from your computer for a while. Be patient and you will be rewarded!
If something in this process doesn't work, I'll do my best to help. Just let me know what you need.