Material Reversion made Impossible

[Vowgan]

I had converted my materials for an upload then closed my project, coming back to it in three days. When I came back, the "Revert Materials" button was grayed out. When attempting to use the "Load Material Reversion Profile" no such file existed.
I'm uncertain of any factors that could have led to this, nor do I know of anything that I could link or screenshot that would help in this explanation.