For a long time now every time OneDrive updates (read installs a new version - in the background - by itself - triggered from a scheduled task or something) it opens its container folder in a new dopus lister.
I suspect the normal explorer is somehow ignoring it but when dopus is set as default handler this happens. It happens without any user interaction at all and also defocuses the active window in some cases which is unacceptable.
A solution would be for dopus to just ignore the root onedrive folder when passed as an only argument via the command-line.
It's been doing this for a very long time but it's become a nuisance and has to go.
I've never seen this happen on my Windows 10 machines, FWIW.
You could try adding the OneDrive folder to the Explorer Replacement exclusion list to see if that stopped it opening in Opus. (It may start opening in Explorer instead.)
Good idea. I didn't think of that to be honest. I'll give it a try right away. Happens only when you never turn off the PC so I wouldn't be surprised if only a few people ever experienced it.
I am having a similar issue. Every time I scan a document or save one a document to OneDrive a new lister automatically opens to the location it was saved to. I can't figure out how to make it stop. Can someone help me with this? I'm new to OD and this forum so my apologies if I am not submitting this question correctly
If you turn off Explorer Replacement (Preferences / Launching Opus / Explorer Replacement), wait a minute or two, then do something that triggers the issue, does it still happen? Do you get a File Explorer window opening instead, or something else, or nothing at all?
In the same place you can also add folders to a list of exclusions which Opus will ignore if something asks Explorer to open them.
Sorry for the delayed response. In the interim, I have actually changed computers. I got this problem resolved previously. I just can't remember how I did. Anywho, I am using DO on my new computer (current version) and I am having the same issue. I tried the steps you provided but Explorer opened instead. The same thing happens when I exclude the folder (if I am doing this correctly under the Explore Replacement option). For context this primarily happens when I scan a document. The application I use for scanning automatically saves the document to a folder on my OneDrive.
That's different to the folder opening out of the blue when OneDrive updates.
Turning on Preferences / Launching Opus / Explorer Replacement / Open external folders in a new tab should be all you need to do, unless the program launching the folder is doing something unusual.
When I select "Replace Explorer for all file system folders" Opus opens.
When I select "Replace Explorer for all but the following folders: excluding the folder on the OneDrive that scans save to." Opus opens.
When I select "Replace Explorer for all but the following folders: excluding the folder on the OneDrive that scans save to and "Open external folders in new tab." Opus Opens.
When I select " Don't replace Explorer." Explorer opens.
So the scanning software is asking for the folder to be opened. It's always going to open a new window (or at least a new tab), whether in Opus or Explorer, unless there's a way to tell the scanning software to stop doing that.
Is the aim to stop anything opening at all, or to keep the folder opening but open it in a new tab instead of a new window, or something else?
If the aim is to stop anything opening at all, the problem needs to be solved within the tool that's asking for the folder to be opened, not in Opus or Explorer. There may be an option in there somewhere, but you may need to ask the developers of the scanning software for help on that.
Oh silly me! You were 100% correct!!!! It was an option right there in the scanning application settings...just sitting right there.... big as day "Open folder after saving" with a big check mark next to it! Thank you!!!!!
You were 100% correct!!!! 
It was an option right there in the scanning application settings...just sitting right there.... big as day "Open folder after saving" with a big check mark next to it! 
