cant load builds either

Same here

the models i was editing last night are no longer accessible even saves from before the bug do i have to build it all over again?

I know its a bit late but it might help someone else. I got the error and managed to fix it. I think it was one of these 2 problems:

1. Hidden parts. I had a hidden part that I made visible and deleted.
2. Bugged parts. I had 2 parts that had stuck. I marked the whole model and moved it. All the parts that didn't move with the model was bugged. To select them I looked in the "Graph" at the right side of the screen and selected them from there. When selected I moved them and they could then be deleted.