[Sheepdude]

Edit: It does work with a fresh server build and the latest MM:S and SM. I really don't see why it's crashing my other server, it's very bizarre.

Nope, it is definitely, 100% a problem with the plugin, CS:GO, and switching to a custom map. I ran srcds with nothing but this plugin and changed the level to a custom map, and it's a clear crash. This is with SourceMod 1.5.0 dev 3664 and Metamod Source 1.9.1-hg798. If you can change to a custom map with the plugin loaded and not crash, please let me know what SourceMod and Metamod version you are using.