Planning Analytics 2.0.5 (PAX)
Microsoft Windows 2016 Server
When you select a TM1 server in list of TM1 connections in Planning Analytics for Excel a HTTP 503 error appears.
If you test the connection to PAW in the options box it is OK.
Inside the ADMINTOOL for PAW (planning analytics workspace) the value for TM1 Application Server Gateway URI is wrong, it may point to HTTPS when it should point to HTTP.
This if you have changed your setup of TM1WEB(WLP) from HTTPS to HTTP to do some testing.
Copy the URL to a web browser (IE) and test if you can surf there.
Example of URL are: