If you manage to get it back, it would prolly be wise to clear all the history for all the pieces. The error maybe stored somewhere in the history. Do that and then save under a new name as an ma
Do you save your scenes as .MB or .MA? I've learned that .MA tends to be the safest choice - that way, if a file refuses to open or crashes on load, you can at least attempt to debug it (launch Maya with script editor set to show all code, then load the file and see if anything shows up as failing to evaluate - it's…