First, let me say I love this mod. The majority of my time playing Factorio is with Factorissimo enabled.

Two of us have been playing on a map for a long time, and probably due to excessive exploration, one of our computers can't finish "catching up" unless the map is paused, and stopped being able to keep up with the server at all. To solve this, I saved the map, converted it to a scenario to use the map editor, used water to "crop" out all of the extra alien-filled land that had been explored, and re-converted from scenario to map. This took four tries, as the conversion back to a map crashed the first three times. The last time, everything looked like it worked, my character has its full normal inventory, but I can't walk into or pick up any factory buildings.

We have two mods enabled:
Factorissimo2 v2.1.8
Power Armor MK3 v0.1.2 (jimmy_1283)

Here is the save file (145mb):
https://www.dropbox.com/s/2tw26fp6iikscls/factorissimo-newcrop.zip?dl=0

I hope you can find a trick or quirk that makes it easy to fix. My guess is that there's something going out of an expected range of some sort due to the size of the map, and that broke the coordinate connection to the factories somehow, but that is a complete guess.

Thanks so much for your efforts!

Unfortunately the map editor erases all mod-specific custom data from saves, since that data is technically part of the save, not the scenario. Factorissimo2 has a LOT of custom save data, for example it needs to remember how many factory buildings exist, or which factory building belongs to which interior, or which connection has which setting, or what are all the hundreds of auxiliary entities that belong to a specific factory building.

By converting the map to a scenario, you've erased all that data and broken everything Factorissimo2-related in that save. I can't help you with that.

If you still have a backup of the game file, this mod claims to do what you need https://mods.factorio.com/mods/Strath/DeleteEmptyChunks

@MagmaMcFry
Well, that is an answer. Not extremely satisfying, but about what I expected: something I did.

@bitbased
I do still have the original map, so I will check out that MOD. Thanks!