'hl2.exe has stopped working' when I run demos

Solution 1:

Well, if you recorded them on YOUR system, they should be saved in the Garry's Mod demos directory:

C:/programfiles/steam(or valve)/steamapps/<Username>/garrysmod/garrysmod/(demos folder)/(name of the demo)

Or on an Apple iMac:

~/library/Application Support/Steam/steamapps/common/garrysmod/garrysmod/(demosfolder)/(name of the demo)

And for you few on Linux, I am not too familiar, but I imagine it should be about the same as the other two.

In each of those directories, there should be a demos folder named something like demos or possibly recordings and from those folders, you can find your recorded demos and play them or do whatever.