Can't open or view images directory in file manager

Hi all,
I have Revolution 2.2.7 and since upgrading (don't know if that caused it though) the specific directory /assests/images is visible in the manager but I can't view the subdirectories. Initially it has the little triangle but after clicking, that just disappears.

Strangely, I can rename it to images2 and then all is fine and I can also create a new directory. The problem is I have hundreds of images pointed to in html tags in countless places and renaming the directory would break all of them and I'd have to manually find them all and change. I'd like to avoid that and also what's to stop the same problem from occurring again with the new name?

Advice/help/ideas are greatly appreciated.