If your build failed at the assets processing step, the first thing to check is if your MSBuild path is set up properly in
Luna UI > Advanced Settings.
If not it could be that your playable includes a script that makes use of an API we do not support, in this case you can make use of our Scripting Defines to preprocess any lines that call upon this API.
Or if this API is being used throughout a script, and this script is not necessary for your playable to work, you can exclude the whole script using our Code Excludes tab.
You can read further about compilation errors and how to fix them here.