Trouble Shooting

Issues and workarounds

Issues and workaround can be found in issue tracker. Please use the search function before posting your issue, your problem might have already been answered.

If the plugin crashed the editor, please send us your crash log to help us figure out what is going wrong. The crash log can be found in Saved/CrashReport. If you can not find the crash report, you can also send us the core dump file.

Supported Unreal Engine Version















Client Support

Python support for python 2 and 3 are verified with tox.

Verified projects

Unreal Engine projects are of dramatic different scales and complexity. It can be as simple as just a single room, or be a large city or outdoor scene. UnrealCV is far from perfect and it has compatible issues with some Unreal projects. Here are a few projects we are currently using and have verified that UnrealCV can work well with. If you want us to test a map (project), please let us know.

Here are a list of Unreal projects that we tried and verified.

Known issues and solutions

We tried our best to make the software stable and easy to use, but accidents sometimes happen. Here are a list of issues that you might find. Use the search function ctrl+f to search your error message. If you can not find useful information here, post a new issue. Subscribe to an issue if you want to get future notification.

  • python3 support. See issue #49, Thanks to @jskinn for the idea!

  • The screen resolution is not what I want

    • In editor, change Editor preference -> Level Editor -> Play

    • In the game mode, use console command setres 640x480

    • Change the config file shown in vget /unrealcv/status

  • The speed of UnrealCV

  • The OpenEXR requirement

  • The Unreal Engine config file not changed

  • The image and ground truth not aligned

  • Can not connect to the binary

Use vget /unrealcv/status to make sure the server is listening and no client is connected.

Platform specific issues


When in mac, the server can not detect the socket disconnection. If the first time connection is successful and the second time is faile. Then please close and re-open it again.

Native error= Cannot find the specified file

Invalid SDK MacOSX.sdk, not found in /Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs


  • The binary can not run

    For example an error like this.

    [2017.05.25-04.14.33:476][  0]LogLinux:Error: appError called: Assertion failed: Assertion failed:  [File:/UE4/Engine/Source/Runtime/OpenGLDrv/Private/Linux/OpenGLLinux.cpp] [Line: 842]
    Unable to dynamically load libGL: Could not retrieve EGL extension function eglQueryDevicesEXT

    It is very likely an issue with the OpenGL of the system.

    sudo apt-get install mesa-utils and run glxgears. Make sure you can see a window with gears running in it.