I'm using Web Companion to host databases which are accessed using CDML/HTML files. Web Companion is configured to use Port 591. About 20% of users aren't able to access the HTML files, likely because their firewalls are blocking 591. So, I switched everything over to port 80.
Now, I can see the pages when testing this through port 80 but no one else can. Any ideas?
Are you using a web server like IIS or Apache, or are you using FileMaker's built-in web server? If you're using a seperate web server, is it forwarding filemaker requests to the correct location/port?
Also, try restarting FileMaker and see if that solves it. (Sometimes it seems to need to be "reset" in order for changes to take effect).
Is the machine on which FileMaker web companion is running exposed directly to the internet, or is it behind a NAT box or router? If its behind a router, is it forwarding traffic to the new FileMaker port? If its behind a router, is it possible that a different machine is receiving traffic to port 80 behind the same external IP address?