I've read a couple places that some people have to pick a different version because they broke some achievements in later builds. I wasn't able to obtain any mission related ones for example. There's a code you enter in preferences for the "pre-mod_test" version (id post it but im not sure about Steam's policy on sharing betas codes but anyone can look it up). Someone named "Kes Gaming" on YouTube has a good video on this.

Sadly I learned this way too late too and I'll have to start over.

(ik old post but I didnt see anyone recently talking about this existing problem)