Hey there, long time and returning customer. Started a new server last night and put on a few trusted mods (Structures Plus, Dino Tracker, Immersive Taming, Better Dinos, and Super Spyglass). All mods I've used before, but times changes. I kept getting Mod Mismatch errors "Please make sure the server is running latest versions, etc. etc."

Having seen this before, I started going through the mods to see if any were out of date, and yes, a couple of them were older, so I removed those, replaced with updated versions (Super Structures, Binocular) and tried again. No luck. Removed everything and server came up fine with no mods at all. Started adding mods back one at the time.

After a dozen restarts, I have managed to get exactly two mods to load: Better Dinos and Immersive Taming. It will not load any of the current Stacking Mods. It will not load either Super Structures or Structures Plus (with OR without the Homestead integration turned on, I tried both!). It won't load anything, it seems, except the two mods I listed above.

Now, I am willing to believe one or two of these popular mods might be out of date, or Steam is mucking them up as they do on occasion (Dino Storage, for instance, is totally broken right now because of Steam) - but I've done a pretty good amount of troubleshooting and have set up numerous mod-filled servers here ... so, am I missing something? Can you help me out here?

Mod Mismatch means that the files on the server for a mod do not match the files that are on your local PC.

This error is fixed by one of three solutions:

1) Verify local files.
Due to the increased bandwidth demands due to COVID, SteamPipe (The platform Steam Workshop uses to install mods and workshop content) has started throttling heavily. This can cause a disconnect due to the coded timers for ARK timeouts. ARK wasn't designed to install with a trickle of a connection. A Verify can correct any local files by simply re-installing damaged files.

2) Perform a server rebuild. 
A server rebuild is as close to a server verify as one can get. It's possibly needed for the same reason a local verify.

3) Perform the local Steam Cache last resort process. I'll post the full process in the next message. It's important you do every step, in order. To date, anytime I've had a mod mismatch, doing step 1, then step 2, then occasioanlly step 3 (which will be posted next) has never failed to fix a mod mismatch on any host, or in my private home servers.

Mod Mismatch / Steam Cache Purge - Last Resort Process

1. Stop ARK if it is running
2. Create a list of all your ARK mods in the Steam Workshop
3. Unsubscribe from all ARK mods in the Steam Workshop
4. Delete the installed mod files by deleting all folders and files in “Steam\steamapps\common\ARK\ShooterGame\Content\Mods“
5. Delete the cached download files by deleting all folders and files in “Steam\steamapps\workshop\content\346110”
6. Restart Steam
7. Re-subscribe to your mods from your list (it is best to use the steam browser or web browser, joining a server is not a good idea)
8. Click this link > steam://validate/346110 and Let this process finish. (It can take a VERY long time.)
9. Start ARK and wait for the “Installing” text in the bottom right corner to vanish.
10. Done!