I took a quick look at the file and everything looks alright on your end. Nothing wrong in the logs or the save file. I'll have to do some tests but if I had to guess, then it probably has something to do with the cargo capacity bug. I'm not sure how to fix this for your current game though. Will let you know if I find a solution for you.
As an aside, I noticed you've stationed some aircraft on some of your infantry units. :`)