I have now got the Advanced-Camera-Tools loaded and tried what you did. AND I too get a weird error with a new SKP.
I don't get the error with your SKP though
***
I suspect that its because the advanced camera tools make a new Scene tab that is somehow 'observed' and if you do anything to it it kicks off! - the exporter first changes to that scene-tab which seems to be enough to break things.
There is a fix...
First
don't export and render using the ACTool's scene-tab 'Camera 1 [FS]' as it might break...***
Instead there are two workarounds for this...
One - Right-click over the tab and use 'Add' to make a new scene-tab with exactly the same settings 'cloned' from it... BUT without the pesky 'observer' to make it fail - it works OK for me then.
Two - Alternatively just change to the 'Camera1 [FS]' scene tab view and then export using 'from <Current View>' camera option instead of the named scene-tab itself, this should also work OK...
***Strangely as with your SKP, I have found that if you do these changes to my new SKP, and later on I export using that very same 'Camera1 [FS]' scene-tab it WILL work OK
I need to clarify with Google what this new Camera tool is actually doing with this scene-tab - as it is a pain!
It might also break 'animations' if it kicks off part way through...