> Please include the exact error so you can be helped. Thanks.
I think information that may help is if you are using SSL, is there any error reported, what browser you’re using and if the pdf that you are trying to “attach” is actually a link. There is a bug in Internet Explorer using SSL and accessing pdf files. That is just one example.
It could also be something wrong with the pdf file too. Have you been able to attach other file formats?