I escape the planet, escape the ambush on the first mission. See the debriefing screnn, and one more showing status of units. Next screen shows the hints in the top left, and the mouse arrow, but otherwise black. Followed the support link to CCCP codec pack. Downloaded and installed, but didn't uninstall anything else first. Wasted money? Not happy.

You may want to skim the Battletech support forums to see if anyone has reported something similar:

https://community.battletechgame.com/forums

Or the local version here:

https://www.gog.com/forum/battletech

If you decide to post other there, make sure you give your computer specs. From previous threads, a lot of folks are trying to play this game with bare min specs and that's probably what's causing a lot of these issues.

A good rule of thumb is to always include specifics when asking for help.

Good luck