Stay away from Microsoft OneDrive! But not that far away...

Update 14 December 2019: Microsoft seems to have fixed the problem mentioned below. I just connected with another computer, and with the same manipulations I did below, everything worked reasonably well. Caution still needed, however.

My previous post was about how great it was to have all my data in the Cloud, in case I lose my laptop. It is only fair that I now describe the disaster that a cloud service can cause. In this case Microsoft's OneDrive.

For many years, I have chosen to sync a few folders from OneDrive to my local storage on my travel laptop, so they can be indexed by Spotlight. The rest of the folders are huge, and I see no reason to keep them locally on all devices.

A few hours ago, I tried to connect to a city library WiFi. The library had problems with their certificate, and after a few attempts, I gave up. However, OneDrive eagerly asked me to add my credentials again, asked me to select my local folder (which has not changed for years) and as soon as I got on a more reliable network, it started downloading my entire OneDrive to my local storage. This process blocked my laptop, it blocked the Preferences panel of OneDrive, so I could not even access the place to stop the disaster.

OneDrive, enthusiastically created folders all over my local storage, and when I after twenty minutes finally managed to tell it to stop the mayhem, it told me that it had 16000 changes to to through. It blocked my computer with 16000 things that had not happened.

The panel where one selects folders to download finally appeared, but it was still frozen, so it took minutes to scroll down the 15 items and to unselect the folders I had never selected to start with.

I then disabled their deleterious "Files On-Demand" service, which I had never asked for or enabled.

After two hours, I now have a sync message, which says that OneDrive "needs my attention" to solve problems Microsoft's incompetent programmers have caused. Five folders "already exist" in the "same location online". I never created those folders! Microsoft's disastrous software did. I have no idea what will happen if I delete, rename or copy those folders, and I bet neither does Microsoft.

Update: The way I got out of this may or may not have avoided disaster, but I think it was reasonably safe. I took the following steps:

1. Rename all the folders with "problems" according to OneDrive. I added "- garbage" to the end.
2. Wait for all the garbage folders to be uploaded to OneDrive.
3. Check the file list in the web-interface to OneDrive. Make sure the files are there, and that they are unlikely to contain data that is in the original folders.
4. Delete the garbage folders using the web-interface.
5. Wait for OneDrive to sync and removing them from my local storage.

I do not know if this was the safest or quickest way of rescuing my folders, but it seems to have worked.