[mirela]

Invalid Attachment specified. If you followed a valid link, please notify the administrator

[dc/dc]

You must post an attachment with a valid extension. The valid extensions are listed in the attachment dialogue box. Also, I believe you must have a certain of posts prior to posting attachments.

[daphne]

I think you cannot post an attachment until you have a certain number of posts. Why are you trying to post an attachment?
Or were you trying to view an attachments? Some attachments are no longer available due to changes in the forum software.