Neither SuperUsers nor any other users are able to upload attachments.  Both get the same message (below).  I am also not able to disable attachments; all controls on the page disappear, to include the submit button, if I uncheck that box.   It says the folder name cannot be null, but that is set, too.

Here is what is set up (the default path was Forums/Attachments - that produced the same error):

the folder exists:

It would be nice if I could take attachments offline until they are working but that isn't even possible at this time.

I saw another post that seemed to be about the same issue but it was on an older version and the file that was referenced doesn't appear to exist in Forums 5.0..

Any ideas?  Your help is much appreciated!

JoAnn

Found it.  I am able to disable attachments for now.  Thanks.

It takes out the attachment control under the editor. Note that editor may still allow adding attachments as well. For that there is a separate setting in editor.