I have problems up manuals

Hello to all the forum members of this excellent website, from which I've downloaded valuable information that has cleared up many of my doubts. I'd like to mention that when I've tried to upload a manual, I get the following message: "Login has been refused by antispamming system."
If anyone knows how to solve this problem, I would be very grateful, so I can contribute my two cents with the information I have.
Thank you in advance, and I look forward to your help.