Basically the mod mismatch can occur when steam forgets to do it's job and update a mod as it should.

This tool will delete all your Mods, and can back them up as well if you have Winrar or 7-zip. It can also do the same for multiplayer servers themselves. If the servers mods are the issue this tool can delete/backup them as well!

Then all you have to do is restart steam, and go to the workshop... sub, and unsub a random mod to kick steam into action mode so it can download all of them correctly this time!

This DOS script was made for Windows 10, and I can't guarantee it will work with every set up. This is because of things such as, custom steam libraries locations, Winrar & 7zip not being installed in program files.

It's not perfect but, I decided to put it out here for any others that might find it useful.

(UPDATE) Now has the ability to create a mod list, This option will sift through your locally hosted server and list all the mods it uses. You can then send this to friends who play on your server, and if they put this .txt file into the same place as this Multiplayer Utility.bat it can then selectively delete mods that only the server uses.

This helps save time, since some might use more mods in solo than your server uses. This keeps them from having to download every mod they own again, but only the ones that are strictly needed!

Copy this, and save it as a .bat file[pastebin.com]