Why is this happening?!

So i played the game yesterday, like i always do and today, when i try to launch it, it says it must be installed again. I did NOT uninstall this game!! It has never done this before!! All of my mods that i installed and the custom configurations i have are going to be LOST NOW!

 

There's a possibility that the game is still installed, it's just that Steam is for whatever reason no longer recognizing the installation files. So, attempting to re-download the game should cause Steam to recognize the existing files. You can also copy and paste your user folder somewhere if you're worried you'll lose your mods and configs.

 

Even if the game was uninstalled, all the mods and configs would be left in your documents folder, so don't worry

 

Thanks!