Self-inflicted pathing problems might not be easy to see issues

[ksuquix]

If you end up with a combination of names/whatnot that a rename tries to move the current model to a subdirectory of itself, it randomly fails without a good error. Perhaps returning the text error of the failed "rename" system call would be good.

[ksuquix]

permissions problems etc probably fall into this same category.

[Floppy]

This should be improved by #1254, but moving a model to a subdir of itself will still probably explode unhelpfully.