5 WebDAV Mount Gotchas That Will Eat Your Files (And How to Avoid Them)

5 WebDAV Mount Gotchas That Will Eat Your Files (And How to Avoid Them)

WebDAV has been around for almost thirty years. It is a small, honest protocol. But the moment you point Windows Explorer at a WebDAV endpoint and start dragging files around, a handful of edge cases can quietly corrupt data, lock up your apps, or make a perfectly good drive letter disappear. Here are the five I have seen bite the most people, plus what I do about each.

1. Opening a file, then losing the network

WebDAV clients are supposed to keep the file open across reconnects. In practice, when the connection drops mid-write, you have two bad options: the client either errors and leaves you with a partial file, or it silently retries and you end up with a duplicate write when the link comes back. The fix is to make sure your mount client handles reconnects the way a network share does, and to use a tool that does not paper over the failure. If you mount with net use, you get the Windows default behavior, which is the worst of both worlds. Tools like ScsDriver register a real drive letter with reconnect logic that matches what you get from a UNC path.

2. File size limits on the default Windows WebClient

If you copy a file larger than about 50 MB to a net use WebDAV mount, Windows will silently fall back to a slower path and sometimes time out partway through. The fix is to either patch the registry to raise the FileSizeLimitInBytes value, or use a different mount client that does not have that limit. The same issue applies to big files in the other direction.

3. Apps that hold exclusive locks

SQLite databases, Outlook PST files, Lightroom catalogs, and several virtual disk formats use exclusive locking. If two processes try to open the same file through a WebDAV mount, one of them will get a sharing violation, or worse, both will see what looks like success and write conflicting changes. The fix is to know which of your apps do this and either keep the catalog local, or use SQLite WAL mode and one-writer-at-a-time discipline on the share.

4. Path length and character set

WebDAV is supposed to be UTF-8, but some servers normalize, some do not, and Windows clients tend to do their own normalization. The result is that a file named Reseñas.txt on the server can appear as Rese~as.txt in Explorer, and the rename round-trip can lose characters. The fix is to stick to ASCII filenames for anything important, and to test character set handling on a few sample files before you trust the mount with real data.

5. Caching and the ghost write

WebDAV clients cache aggressively. If you edit a file in two places (say, a local Office copy and the network share), the last one to sync wins, and the other one is silently overwritten. The fix is to either use a tool that does not cache by default, or to make a habit of closing files before you move them.

What to look for in a 2026 mount client

The good news is that the problem space is well understood by now. A 2026 mount client should:

• Reconnect automatically when the network flaps, without losing open file handles
• Not have the 50 MB file size limit
• Be explicit about its caching behavior
• Mount as a real drive letter, not a network redirect
• Survive reboot without a manual script

I have been using ScsDriver for the last few months on a $5.5 lifetime license. It ticks all five boxes above, and the install was about two minutes. If you only need to mount a single WebDAV endpoint and you do not want to own the storage stack, it is the shortest path I have found.