Hey simmania -
Is it possible for you to share the project which is generating this error for you? If you need to keep the download link private please feel free to message me on the Forums. In the meantime, also try deleting the Saved and Intermediate sub folders out of your project’s directory. This will force a recompile of all shaders on the engine’s next load of that project and may clear up an issue caused by compile errors.
Thank You
Eric Ketchum