Read this document:
If you're not familiar with proxies and networking voodoo then pass it off to your IT support so they can help you with a fix.
I don't know networking stuff but when I gave the above to my networking guys they said the document helped them create the necessary rules and proxies.
Thank you Toby. No luck.
The basic Tableau TMS work, not mine's. The IT dept told me the server is not under a firewall, has clean access to the net.
Could you try my TMS in a viz, publish to your server and let me know if it worked? I'd really appreciate it!
Ok, with IT found the problem. They had to upload the TMS file to the server and change the parameter
mapsource inline='false' to 'true' and worked!