This is also happening to me. I run Linux Mint 14 64bit
I get this error when trying to launch it

jeggy@jeggy-mint /opt/dungeondefenders/UDKGame/Binaries $ ./DungeonDefenders-x86
Segmentation fault (core dumped)

I tried running this command "MESA_GLSL=dump ./DungeonDefenders-x86" and i got this long here, but still didn't work
http://paste.ubuntu.com/1457339/

(In reply to comment #1)
> This is also happening to me. I run Linux Mint 14 64bit
> I get this error when trying to launch it
> 
> jeggy@jeggy-mint /opt/dungeondefenders/UDKGame/Binaries $
> ./DungeonDefenders-x86
> Segmentation fault (core dumped)
> 
> I tried running this command "MESA_GLSL=dump ./DungeonDefenders-x86" and i got
> this long here, but still didn't work
> http://paste.ubuntu.com/1457339/

That's a different problem though. It looks as if your hardware doesn't support GL_EXT_bindable_uniform, that should be filed under bug 5823 (https://bugzilla.icculus.org/show_bug.cgi?id=5823) which it appears you have already done. It appears very different from this bug though. If your hardware doesn't support that extension, then you are out of luck for the time being.

I'm running into the same problem. I'm running Ubuntu 12.04 with the nvidia-experimental-310 driver installed. 

In the first mission I had the game segfault when I hit shift and control at the same time (Also had post-processing turned on). Tried turning post-processing off and being more careful with my button pressing. I was able to get through the second mission with no errors, but now the third mission segfaults at random points. Managed to make it up to wave 5 once. 

It's happened when hitting shift, rotating the camera, and even at one point while I was just walking. And just in case it matters, I've been playing as Series EV, all missions on Medium with Hardcore turned on. Local only so far.

I've got the same problem.  Debia squeeze, amd-x64, nvidia drivers 310.19.  Sometimes the crash happens after a minute, sometimes it takes about 20 minutes.

Is there any progress being made at all here? It's been nearly a month and I don't see anything happening for this or any of the other serious issues reported. It would be nice to at least have some idea of what is going on, is anybody even working on fixing these issues? Is there something I could be doing myself perhaps?

(In reply to comment #5)
> Is there any progress being made at all here? It's been nearly a month and I
> don't see anything happening for this or any of the other serious issues
> reported. It would be nice to at least have some idea of what is going on, is
> anybody even working on fixing these issues? Is there something I could be
> doing myself perhaps?

what characters are you using? for me, using the Series EV in any way causes random crashes (described in Bug 5847) and the backtrace I get is very similar.

(In reply to comment #6)
> what characters are you using? for me, using the Series EV in any way causes
> random crashes (described in Bug 5847) and the backtrace I get is very similar.

Happens for me with Apprentice as well, I'll try with the squire a little later today.

(In reply to comment #7)
> (In reply to comment #6)
> > what characters are you using? for me, using the Series EV in any way causes
> > random crashes (described in Bug 5847) and the backtrace I get is very similar.
> 
> Happens for me with Apprentice as well, I'll try with the squire a little later
> today.

Sorry for the delay, was a bit busy and then the site was down. Tried with squire as well, got through the first level, but still a segfault in the second. It doesn't look like this problem is class-specific.

*** Bug 5859 has been marked as a duplicate of this bug. ***

Is there some additional data we can provide to assist here, some debugger we can run on it or anything? Just tell me what to do.

All it ever says in the console is...
Game update: AppID 65800 "Dungeon Defenders", ProcID 4295, IP ***.***.***.***:50652
Segmentation fault
Game removed: AppID 65800 "Dungeon Defenders", ProcID 4295

This doesn't seem to be tied to any particular hero class as others have suggested (as far as I can tell).
It is however, much more frequent in higher level games. A nightmare match is almost guaranteed to end in a segfault at some random time.
If I host a crystalline dimension game on any difficulty, it will segfault at some random time before the last map. Sometimes right away, sometimes it will let us get three maps into it. If I join such a game, I will still crash. The only way I was able to complete it was to join a game just before the other players began the final boss fight.

same problem......

Same here:

Game update: AppID 65800 "Dungeon Defenders", ProcID 32357, IP ***.***.***.***:61119
Segmentation fault
Game removed: AppID 65800 "Dungeon Defenders", ProcID 32357