I kept losing my skin weight data every time I reopen Maya

[Anonymous]

I rigged a character with the Advanced Skeleton plugin in Maya 2020, and I spent some hours painting all the skin weights till the character deforms the way I want it and all is perfect! Everything is working and good...

I saved my progress and closed Maya.

When I reopened scene the next day to make some updates, I discovered that when I transform the controls, the character geometry no longer deform with the rig, and when I checked the paint weight window, I discovered that all my skin weights are gone for all the joints...

I unbound the skin and rebound it again, spending more hours repainting all the skin weights, and when I was done, I saved the progress again... I then closed and reopened Maya to see if the issue is still there, and alas! It's still the same issue...

I am really confused here and don't know what's going on... How do I solve this issue? Someone please help me out here... 

[hamsterHamster · Accepted solution]

Do you have any construction history on that skin mesh (even UV editing), besides the deformer clusters? Go Edit>DeleteByType>DeleteNonDeformerHistory.

Also, to be safe, select the mesh and go Rigging>Skin>ExportWeightMaps.. set it to some 2048 at least. You will be able to import it back if something else breaks.