A common cause of crashes on built applications using our SDK is missing files or folders, like the glTFRuntime materials. To fix this, you can adjust the packaging settings by going to:
Edit > Project Settings > Packaging
From here, expand the Packaging section and look for "Additional Asset Directories to Cook." Alternatively, you can search for this setting from the top of the Project Settings Window.
Now add the to folders "ReadyPlayerMe" and "glTFRuntime" as shown below.
On the glTFRuntime documentation page, you will also see this tip for fixing build issues.