Save files randomly delete ships

[Artheus]

Hello everyone!

As the title already says, in my modded main install are frequently ships going missing (at least 4 by now, 3 of them interplanetary) . I did not remove any modpacks required for them. The Victims are manned, unmanned, modded or stock. It even happened when I did not have anymods installed but KAC and graphical ones. For saving before closing the game, I use the Save button on the escape menu in the KSC view. I tried manually editing the ships from previous saves where they still existed in, but failed and nothing happened.

I also can't load previous save files from the escape menu, as the game crashes when I try to do so. When I have set up an alarm for that vessel and it dissapears, KAC states "vesselID not found". It seems to be a variation of the nullspace/hell kraken, as when I have last switched to a vessel that went to the grave some saves later, the altidude meter changed to white, speed went to NaN, black main screen. The only way to fix it was alt-f4 to save the vessel, but it also happens when I do not switch to the vessel before, it can randomly dissappear at any time as I feel. Does anyone know a trick to edit the save mechanic to prevent this or some other tips? It really bugs me out, lost the Eeloo rover, a manned moho mission,  the 1.000.000 funds refueling station in Kerbin orbit and a contract kerbol refueling station with duna landers on it already.