Weird error everytime I try to use a tool from a save..

It’s happened to me a few times before so I end up saving my stuff on advance duplicator very often.

So here is what happens:
I am halfway done building a big structure or ship, I then save it. I get back on gmod and load my save, I use a tool such as weld and I get that error. For EVERY TOOL. So for that save, my work is pretty much halted until I fix this. So luckily for this project, I got it saved on advdupe. Otherwise I’d probably give up.
Thank God for allowing the man who brought advance duplicator to exist.

Anyway, here is the error:
http://img197.imageshack.us/img197/7744/wtfjme.jpg
its the text in the red box…

Saves are broken; start using Advance Duplicator. And no, there is no way to get back what you saved.

Garry’s mod has terrible support for saved games