This is more of a reminder to myself than anything, and you may already be aware of this, but in case this issue is new here’s what helped me:

While taking our enterprise in a paperless direction, one department was having trouble opening a document library using the “Open in Windows Explorer” function every time they saved a certain file to it. For the longest time I couldn’t find any pattern to the behavior, and assumed it was something to do with the file. Turns out it was the filename itself. In this case, they were using the word “Service” in the filename, namely “<dept name> Service Request.pdf”. The word “Service” isolated in the filename was screwing up WebDAV as it was trying to open the document library in a Windows Explorer view. Once they either removed the word “Service”, altered it (Svc, Serv., etc) or ran the whole thing together (deptservicerequest.pdf) the issue was resolved.

Never would have assumed “Service” is in a round-about way a protected word, like using the word “table” in a SQL query, but apparently it is! Would love to learn more about WebDAV to better understand why this is so, and if there are any other words that should be avoided.

Hope this helps!