So I encountered this problem, when got to stage of the game when this princess girl decided to bomb me to stoneage and I did not even have had AA close to be open for research.
So, these are softlock scenarios I encountered:
1. I had my prison blasted while I have been interrogating a prisoner. Softlock, I cant transfer or sell the one who is being interrogated.
Possible solution, make one prison/den spot inside old world lab.
2. My base was blasted, cause it was cut from lift when my corridor got destroyed (defensive build with 1 corridor), leaving me with only a lift and hangar, after transfering everything to another base I still had something in my warehouse, even when I checked that absolutely everything and everyone was transfered I had like 1,4 or something additional unregistered cargo. Softlocked.
Both times I was softlocked in sell/transfer windows.
Any way you can fix this in later builds? I admit I cheated out of this by instabuilding powerful radars in every blank spot of base, just to deflect these missiles till I researched AAs, cause they spammed me hard twice a month and my interceptors were to slow to catch up with strikes and to weak to destroy all of the scout designators.