引用自 Omega7520：

I found the issue. change your branch to none, just remove your beta branch and use normal gmod. thats the fix. so if your using x86-64 branch, get off of it and the reload sounds WILL be fixed.

Like this user said, you have to get off the x86-64 branch since this issue is unique to that version of Garry's Mod. This is the only solution to this problem for now, as the authors are remaining silent and aren't giving us a proper response.