I have similar issue with saved game file that is 223 MB, but on Windows 10 x64. Error code is 0xC000041D - STATUS_FATAL_USER_CALLBACK_EXCEPTION
I previously had same error code and took every step i could to resolve it including clean install of arma but apparently the issue was with either bandicam fps counter overlay, or ryzer synapse, or daemon tools. One of these (bandicam probably) was corrupting my saves making them impossible to load even with no 3d party apps loaded. When i disabled those 3 forementioned apps i could play without errors till today.
I was able to pinpoint the moment problem emerges to the point of two save files, few minutes apart. In one i'm standing on the pier looking at the motorboat 20m away. This one loads perfectly. In another i've already swum to the boat and took driver's seat. I didn't move anything, didn't started or completed quests, didn't start the boat engine, didn't changed my inventory. I aimed to make as little changes as possible, still second save gives 0xC000041D crash.
I have those two save files and a crash report if needed.