Synchronization of file attachments to online account

I have a library of >9000 articles and 7.8GB in size. I am relatively new to Endnote and have been trying to synchronize my desktop account to my online account. While it is transferring the references it is not transferring the PDF attachments. I have all the attachments in my desktop library as relative links. Is it because the total size in greater than the 5GB limit? The sync status shows no attempt to transfer files, and the manage attachments tab on the online account shows no attachments. If this is the case is there a way to go beyond the 5GB limit or do I have to split my library?

Splitting your library won’t help.  You can only sync one library to an endnote account.  I would contact custormer service, but I have not heard of  a solution to this problem.