Same problem in my campaign soul of the machine. No mods.

Strange: I still can designed and build my own ships. Only the bomber class is still visible.

Decommissioning of fighters has no effect, so it seems not a limit problem.

Version 3.21

I can provide a save game.

Hi there if you could please attach the impacted save file so that our team can investigate the issue, we'd love to get this resolved for you.

I may have run into this same bug. I started this game on 2.31, and progressed through the tech tree until I could build frigates. I actually built several of them at 2 different shipyards, then, some time later, I noticed that frigates were no longer available to build in my shipyard list, I could only build fighters and bombers.

I haven't designed any of my own ships yet, just using the default ships. Also, I haven't obsoleted any ship designs (I know that's caused problems in the past).

Saved game from when I first noticed the problem is here.

After researching the cruiser tech, the default game-generated cruiser design showed up in my shipyard along with the fighter and bomber, but the frigate is still missing.

Seeing the same thing:

• Have 2 fleets with Frigrates in them.
• Look at the Krynn Syndicate's shipyard in the attached saved game file, from Sunday night; no standard Frigrate build option, despite the raw materials being available.
• My Archer Fish frigrate, that I designed in some previous game, is available.
• Playing the same game, and after I added some tech (forgot which one), the AI designed a new Frigate for me, and that now appears as a build option.
• Using the Insider's Build, from late last week (2.2?)
• Wasn't aware that the Op found the same issue, until I started looking for a good place to post my saved game file.

https://www.dropbox.com/scl/fi/scc4iezvju8cyc1h6zi3m/Game_301a.GC4Sav?rlkey=givjysxsde93301pduxf53d7k&dl=0