Launcher for Mac crashes randomly on mouse move

Using Mac OSX 10.10.1 with latest version of launcher, launcher will crash if it is doing something in background and I move mouse.

I can reproduce it about 90% of time by:

  1. Start a background process such as downloading a big thing like content examples, or creating a local shooter game from already downloaded copy in library.
  2. Move mouse, especially two finger scrolling on trackpad.

This usually happens when I start downloading something, and then I start browsing marketplace. crash is basically a beachball that lasts forever until I force-quit.

From UnrealEngineLauncher.log it appears to actually be something to do with mouse movement:

[2014.12.03-21.28.58:546][  0]LogMac: === Critical error: ===
SIGSEGV: invalid attempt to access memory at address 0x0

[2014.12.03-21.28.58:546][  0]LogMac: _ZN17FSlateApplication21ProcessMouseMoveEventER13FPointerEvent Address = 0x930c295  (filename not found) [in UnrealEngineLauncher-Mac-Shipping]
_ZN17FSlateApplication19SynthesizeMouseMoveEv Address = 0x930c138  (filename not found) [in UnrealEngineLauncher-Mac-Shipping]
_ZN17FSlateApplication4TickEv Address = 0x9300c7b  (filename not found) [in UnrealEngineLauncher-Mac-Shipping]
_ZN12FApplication3RunEv Address = 0x8e29e61  (filename not found) [in UnrealEngineLauncher-Mac-Shipping]
_Z24UnrealEngineLauncherMainRK10TSharedRefI12FApplicationLN7ESPMode4TypeE0EE Address = 0x8e2c3a3  (filename not found) [in UnrealEngineLauncher-Mac-Shipping]

This was happening before I wiped my machine yesterday. After I erased my HD and re-installed OSX and everything from scratch (because of other reasons). Still this error happens, but it’s a clean install.

I sent a few crash reports to Apple, but I figured you aren’t checking them because you have your own crash report stuff that isn’t getting run. So I attached a copy of that in crash_1.txt I could upload rest of UnrealEngineLauncher.log if you need it.

Hi smilingrob,

Sorry for huge delay in response! I’ve been trying to get this issue looked at by developers, but it got lost during Christmas break. Are you still experiencing this issue with Launcher? Please let me know if you are. Thanks!

Hey , yes I just got it to crash again doing same thing, moving mouse while downloading. It wouldn’t crash for about 10 seconds, so I started alternating between Learn and Marketplace tabs scrolling with trackpad, and then I got beachball.

However this time it didn’t produce error about a mouse, and instead hung in a “not responding” state for a few minutes before I killed it. While it was not responding I took a Sample of Unreal Engine Launcher in Activity Monitor. Also I got a list of Open Files, and finally after force quitting here is problem report that was sent to apple.

Also while it was “Not Responding” network activity was at 0kb/s, but CPU was at 60% for launcher. However it was not done downloading.

Thanks for looking into this.

Hi smilingrob,

Could you follow 10 steps at bottom of this link and provide your Verbose Logs? They may help us track down issue.


Hello Smilingrob,

Max here from Launcher QA Team! We’re aware of several mouse move related issues on Mac, some of them Crash related. These issues are known and several fixes are in for them in next launcher update. Once new launcher update goes out, Check ans see if these issues still occur. If they’re still happening please respond back to this thread!

-Max B.

I tried to reproduce with new launcher on Mac and it didn’t crash! Nice work, looks and performs great.

Awesome! Glad to hear you’re fixed and ready to go!

-Max B.