petopeto said:
If you're hitting runtime errors, it's probably just out of memory; it wasn't handling OOM in a thread correctly. I've fixed this and I'll update it in a bit, as well as setting the PS hint that tells it how much memory it'll need (which may or may not matter; the documentation doesn't actually say exactly what this does).

I think I tracked down the problem. It seems that your Greycstoration plugin doesn't get along with the Adobe's optional "Bigger Tiles" extension. After removing it, I no longer seem to get a Runtime error half-way through filtering that image.

"Bigger Tiles - On computers with > 1 GB RAM, you can optimize Photoshop to take advantage of the RAM in your system and manage memory more efficiently."

Any chance of making it play nice when using "Bigger Tiles"?

Edit: Maybe that wasn't the whole cause. I just got another runtime when trying to apply the filter again after I had already applied it once. It does seem better without "Bigger Tiles" though.

Also, out of curiosity, what are the valid ranges for all the settings.