I had to find the scene which was causing it to not be possible to preload that scene. Its as if it has an issue loading specific nodes that when taken out, it lets me preload the scene.
How do I track down the specific node and the reason why it stops scene resources from loading correctly?
The error it gives me is that it cannot preload resource at path. Taking out the culprit nodes from that scene, fixes it but I'm still not sure on the best way to look for defects are. I have had a number of issues similar to this.