Troubleshooting World Locking Tools
Annoying issues will be noted here. Also, here's a recommended strategy for narrowing world-locking problems.
World Locking issues
Low frame rate
World Locking Tools should have no discernable impact on your framerate. (An exception is that the visualizations will eventually drag down your framerate after many anchors have been created, but the visualizers are just for diagnostics, not for shipping with your application.)
If you see a framerate drop after adding World Locking Tools to your application, check your Unity logs. That usually means an exception is being repeatedly generated.
"Missing DLL" errors
These errors are usually from the Frozen World Engine DLL. To resolve them, follow the instructions in the setup documentation to upgrade the FrozenWorld engine to a later version. Following those instructions without changing the version number will repair the installation.
Alternately, you can install using the MR Feature Tool. The Tool handles the installation of dependencies for you.
Missing 'FrozenWorld' namespace
Errors like the following (usually a lot):
Assets\WorldLocking.Engine\Plugin.cs(10,37): error CS0234: The type or namespace name 'FrozenWorld' does not exist in the namespace 'Microsoft.MixedReality' (are you missing an assembly reference?)
It's missing the FrozenWorld.Engine DLL. See NuGet Setup.
Alternately, install using the MR Feature Tool and have dependencies installation handled for you.
It's not working
Check the Unity logs for errors and exceptions.
Confirm that your scene camera is attached to at least one other object. See the setup in WorldLocking.Examples.WorldLockingPhysicsSample for an example. If you're doing dynamic camera manipulation, you may need to keep WorldLockingManager informed of the current camera. See WorldLockingManager.AdjustmentFrame and WorldLockingManager.CameraParent.
More general Unity/AR problems
"DirectoryNotFoundException: Could not find a part of the path"
The path has grown too long. See fuller explanation here.
You see "A remote operation is taking longer than expected" message box and then there's a failure to deploy
Check your USB connection. A bad cable, a bad port, or missing IPOverUSB can all cause this problem. But it's probably somewhere on the communication path from your PC to your device.
Missing Windows SDK components
Mismatch between Visual Studio version indicated in Unity versus Visual Studio version you're trying to build with. Check:
Unity > File > Build Settings > Visual Studio Version
Especially dangerous is if that's set to Latest Installed and you have multiple versions of Visual Studio installed.
On HoloLens, application starts up as a slate, rather than an AR experience
If targeting the Unity's built-in VR support, also known as Legacy XR, then check:
Unity > Project Settings > Player > XR Settings
You must have Virtual Reality Supported selected, and the Windows Mixed Reality selected in Virtual Reality SDKs.
If you're using Unity's AR Subsystems / XR SDK, confirm that you've followed all the steps in our Cross Platform using Unity's XR SDK Plugin system article. Likely culprits are:
- Missing one of the required packages.
- The appropriate profile hasn't been set on the MixedRealityToolkit object (if using MRTK).
When the app is built for ARM on HoloLens2, the app stops at startup, ARM64 works fine
The fix is either disable Graphics Jobs under
Project Settings > Player > Other Settings > Graphics Jobs
or just build for ARM64.
This issue has been fixed in Unity 2019.4 and Unity 2020.3.