I've also had this saving error.
Did the scene used to save correctly?
And if so, did this start happening when you updated the mesh?
My issue started once I updated to a new mesh. The mesh wasn't from my company and was not particularly clean. It was basically auto UV'ed.
I tracked the issue down to a single combined piece but couldn't isolate the issue further. The combined piece would save by it self, but wouldn't save with some other parts. I tried moving UV's, running maya geo checks etc. I tried uncombining the geo to try and find a specific piece. It was a 700MB mesh and time was running out so I had to split the scene into 2, where it would then save.
My hunch was it was UV related some how.
I'm curious to know what caused your file not to save.