I found the fix if you have not in 3 years. You must go to the factory storage and take as many boxes out as need to be abandoned so they can empty them back into the factory storage. It fixed the "Aborting mission/no storagespace" for me !
Will this make the ai under your control move smarter? For example the ai tanks I'm commanding drive into buildings on Altis even. So they get stuck on all kinds of things.