I have forgot these info:
FILEMAKER 10 PRO
Thank you for your post.
Port 80 can sometimes cause a port conflict. Switching to port 591 can help because this port is registered and reserved by FileMaker, Inc. However, since you are still getting the error, you may have a router issue.
Do you have access to another machine? If so, can you try on a second machine to see if the problem continues. It may be a system issue.
What is your native language?