I uploaded my .esp to steam and see that it added a .ckm file to my data folder with the same name as my mod, just this extension.

1) What is it?

2) What should I do with it?


3) Thanks!

1) It's a file used by Steam Workshop for... stuff.

2) Nothing. As far as I know, it's safe to delete and serves no purpose in a package uploaded anywhere else (e.g. the Nexus).

Does it hurt anything if I leave it there?

It's the temp archive the system uses to upload to Steam. When you're done uploading you can kill the .ckm and the .bsl file.

dayumn - I didn't even see the .bsl!!
Where does it hide ( note: is that the equivalent to a .bsa; 'cause I didn't upload any archive stuff).

The CK bundles your .bsa and .esp together for upload. It sends the .ckm to Steam, and leaves the .bsl behind but nobody is quite sure why. Downloaded mods from SW only have the .esp and .bsa files.

Thanks!!
You guys rawk!

Hopefully this thread will help others with the same question, too!