I got this bug when trying to add multiple smileys..
You might just have to add them one at a time.
I got a similar error when trying to run the smilies from Photobucket. I had to add them one at a time.
What directory were you trying to open? You obviously cannot open folders on remote systems.
/forums/images/smilies/
Is the directory. I just uploaded 1 by 1.. but it took forever.
The path is relative to the forum root, thus "/forums/images/smilies/" is actually incorrect (should be "/images/smilies/").
Hmm, probably should stick in a default value there though...