Shape Key Oopsie

Well… i didn’t know this would happen… I was modeling part of my mesh as a separate mesh just so I wouldn’t accidentally select the other bits on accident. I combined the two meshes, did some work, and then went to poke at my shape keys to make a WIP image. Weeelll. When I clicked on one of my shape keys it made my entire mesh go wonky, and I had to ctrl+z a few times to get it to go back to normal.

So I’m wondering if this can be fixed by something, maybe by assigning a vertex group to the shape keys, or if I have to redo them (Which would be a pain in the ass lol)

Should I post the .blend file? If I do I don’t want anyone to use it for themselves…

Is there not an easy fix for this? Or do I need to include the blend file so it can be seen what exactly is happening?

This happens sometimes.
Aligorith is working on a script to work around this.