Hello guys. try to do this one, if you have a Steam version, at least:
[FIX] (probably) If your saves disappeared. And black screen too.
While trying to mod the game (half-successfully, can't make them work in separate folder, only with overwriting). I found that changes inside of BATTLETECH\BattleTech_Data\StreamingAssets\data\VersionManifest.csv if you made even slight formatting error in adding strings, may easily lead to two issues, 1) Disapearing of saves, 2) Eternal loading screen on starting campaign or skirmish. Which means that trying to add some mods can lead to it too. More so, there is some people who managed to play just fine for some time, but then can't anymore. Guess what? The DLC for preorders also doing changes to this file and since it hasn't been available in first hours of release (and only has been added when loggining into Paradox account failed for many people so whey didn't had ability to unlock them) and so if this file update has been corrupted somehow...
The fix is deleting file VersionManifest.csv in BATTLETECH\BattleTech_Data\StreamingAssets\data\ and then to verify Integrity of game files so steam downloaded a new one. Saves should appear again.