Here is how my rig looks in 3DS MAX: https://i.imgur.com/P17xFhS.png (https://i.imgur.com/P17xFhS.png)
Here is how it looks when exported to .smd : https://i.imgur.com/XL4VMoN.png (https://i.imgur.com/XL4VMoN.png)
It just completely breaks the left arm on export and ruins all of the animations and work put in. This is for Gold Source so "Gold Source smd" box has been checked while exporting. I've tried everything but nothing is working so far.
My best guess is that the hierararchy for the broken arm was created using one of Max's Mirror functions? Using the mirror function isn't recommended in many cases. However, there may ba a solution.
Click File > Save As... Archive and send me the zip file it creates. I will look at the scene.