It looks to me this error is a time sync issue or maybe Microsoft is temporarily lost in its own myriad of policies and procedures around Onedrive. In my case the message occurs but nevertheless Sharepoint/Onedrive created a Document folder tree on my local disk just fine. A matter of 'just ignore this message'. The fact that it reports "unknown error" is hilarious in this context.
Getting 0x8004016c error in onedrive when syncing shared with me folder for business account
I am trying to sync certain sub folders to the local file explorer for quick access, but I keep getting 0x8004016c errors after selecting the folder and clicking on use this folder and next.
I only really need access to certain folders and it was working before, but when I tried to add another sub folder that I needed access to, it blocked sync access to the folder and gave the "you already are updating this folder". I then added the new folder and the clouds showing that the other folders were connected to onedrive went away and only one folder was now connected. I now keep getting sync errors and not able to sync the folders that I have access to.
The problem is this:
Main company folder
sub folder1
sub folder2
sub folderA under sub folder2: I had access to this on local file explorer.
sub folder3
sub folderA under sub folder3: I had access to this on local file explorer.
sub folderB
sub folderC under sub folder3: I wanted access to this on local file explorer.
I was able to add the sub folderC under sub folder3, but the other sub folders lost the onedrive cloud icon and when I tried to re-enable the sub folders that lost the cloud icon the above 0x8004016c error occurs and now all folders do not sync at all.
NOTE: All folders are shared with me.