Using Auto-Convex collision in the Static Mesh Editor causes UE4 to crash. try it for yourself.
The most recent output to the terminal in my case was " /home/myuser/Unreal/UnrealEngine3DLuvr/Engine/Binaries/Linux/UE4Editor: symbol lookup error: /home/myuser/Unreal/UnrealEngine3DLuvr/Engine/Binaries/Linux/libUE4Editor-UnrealEd.so: undefined symbol: _ZN15HACD_STANDALONE14createHACD_APIEv "