Spotfire Server: Web Player not starting or Analyst client login fails after updating to 14.0 HF-027 or later

Note that the 14.0 HF-027 hotfix (or later) requires the Spotfire Server to be version 14.0.8 or later, see the installation notes:

Warning: Spotfire Server 14.0.8 or later required.
Before you deploy this hotfix, you must first upgrade your Spotfire Server to version 14.0.8 (or a later 14.0.x service pack). 
If you do not upgrade your server first, users will not be able to use Spotfire.
For more information, see: https://spotfi.re/admin-guide-14-0?context=tss_license-upgrade

If the Server is on an earlier version (14.0.7 or lower) and you apply the hotfix you will not be able to run the environment as intended as there will be multiple issues preventing normal operation.