This must be something I have configured wrong but I am having a dickins of a time finding what it is. I have searched the FAQ with no results.
My installation seems to work ok. I can post in my configured forums. However even as the admin I can only reply without an attached file. If I attach a file I get an error like this:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at firstname.lastname@example.org to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
The attachment actually uploads and is my media data. I just never can see my reply in the forum. If I reply with no attached file, the reply works fine.
I have looked in the debug area with no joy even after turning on debug in settings. My attachment limit is 10M, my PHP mem lim = 256M, max post size = 64M.
Any ideas where to look for misconfigured options or something else?
Actually, ANY attempt to add an attachment gives the same results. The attachment is placed in the media area after the upload and the "Server Error" message is displayed. No new topic is created unless the attachment is removed.
I can embed a link to the media library files within the topic (post) and the image shows up inline. I just can't add attachments. 🙁
Why the "wordpress" part in the url?
About your issue: Is that a linux server or Windows?
You can enable STANDARD Wordpress debug (to a log) and see the real error.
Also wpForo has some debug and tools you can use in the admin part.
Do all pass ok? Any issues reported?