Factorio Forums

Non-blocking saves are enabled, i'm not sure what actually caused this, i had factorio open in the background and came back to this when i tabbed back in.

Whenever i try to save it fails and returns a I/O error in the UI, and upon exiting the save the entire game crashed.

I've attached the log, the save file, and the invalid .tmp.zip save file it created

I/O error sounds like a hardware issue, can you reproduce the crash with the save you provided?

Loewchen wrote: Fri Feb 13, 2026 10:13 pm I/O error sounds like a hardware issue, can you reproduce the crash with the save you provided?

Nope, i've been playing on that same save (the last autosave) for a while and i haven't been able to reproduce it. Drive's SMART info shows no issues, firmware is also up to date.

Please post contents of after crash.

If there is no reproduction provided then i am going to throw this into 1/0 magic. Place where it crashes makes no sense (saving a boolean into a stream) except of one scenario that is plausible here and it would be Accumulator::save seeing a corrupted pointer to a control behavior and attempting to save a presumed control behavior at invalid address which goes through layers of code and crashes at the first piece of code that actually uses that pointer (saving ghost flag [bool] of a red wire connector of a behavior's circuit connector, literally the first byte of a behavior saved). That would fall into a memory corruption.