I tried disabling API mod entirely including the mods which use it but I'm still getting UI issues so at this point I dont know if the mod has broken my save or its a different issue entirely.

I've been using the API with no problems for a long time now, however I lately added the "Urgent Orders", "Subsystem Targeting Orders" and "Wing Hotkeys" mods by Allectus. Since installing these mods I am no longer able to open the information tab on any L or XL ship.
I will mention this over on Allectus's page, but thought it worth mentioning here.

I have a save game from before the mod was installed showing the API working just fine with a hand full of other mods. Unfortunately I neglected to save a second instance immediately post mod as the game is still semi playable without it.

Since the mod in question is focused on fleet management I imagine the problem is somewhere in there but I cant put my finger on it just yet.

Perhaps we can figure out where different mods with overlapping functionality result in the same issue in order to more accurately pinpoint the problem.

Similar issues with Waypoint Fields which relies on this mod. Disabling SirNukes Mod Support APIs and all mods that rely on it has fixed it for me. Luckily It wasn't working from the outset so I didn't make any progress with them active, as it also appears to break saves.