Hey, we have been having numerous bug issues with BG Renderer and AE CS6, we noticed that it doesnt say it is compatible with cs6 and that the last version was written over 2 years ago (may 2011). are you still supporting this? are you going to release something compatible with cs6?
This is not a CS6 related issue. The problem here is that After Effects is unable to read the project file and since it cannot open the project to render the rest of the calls fail which is why the last two errors happen. I would make sure that AE has full read/write permissions to the folder where the project file is stored.