On linux, with build 4.7.1, and even the latest github code, the editor crashes while trying to go through the function CacheOptimizeIndexBuffer in MeshUtilities.

Changing the allocator to ansimalloc doesn't change anything for me.

I disabled mesh optimization for the moment, and the editor starts and I can work, in fact everything works except that feature for the moment.

I have an AMD A8-4550 APU with an HD7640G and I use mesa opensource drivers as the Catalyst driver just crash the whole linux disto on boot.

I am using Ubuntu 14.10 and I tried default mesa drivers (which aren't compatible with UE4 at all) so I am using the latest graphic drivers PPA from : https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers

Searching the internet, I also found a bug report on mesa list about this problem, and it is listed as "NOT OUR BUG" https://bugs.freedesktop.org/show_bug.cgi?id=86471

Thank you.