TIBCO Spotfire Analyst/client can now be downgraded to the older version by connecting with the deployment area of previous TIBCO Spotfire Server version.

All Supported OS

It is possible to use both newer and older versions of Spotfire Analyst client together the current version Spotfire Server. It is possible to downgrade all Spotfire installations after version 7.13 back to version 7.11 LTS.

For example, if you are running 10.3 LTS, you could downgrade to 7.11, 7.12, 7.13, 10.0, 10.1 and 10.2. Note that if you downgrade to 7.12 you will not be able to downgrade from that version to 7.11 LTS, because the functionality to downgrade is not available in that version. First upgrade to a higher version then 7.12 and, from there, downgrade to 7.11 LTS if that is needed.

Below is from the TIBCO Spotfire Analyst/client release notes - 

Newer and older versions of Spotfire Analyst client can be used to connect to the current version of Spotfire Server in order to upgrade or downgrade the client packages. However, it is recommended to always run the same version of client and server in production environments. 

Backward compatibility check of TIBCO Spotfire Analyst for previous Spotfire Server version

https://docs.tibco.com/pub/sfire-analyst/10.8.0/TIB_sfire-analyst_10.8.0_relnotes.pdf?id=0