The TFS values in the error are related to cumulative updates that have been installed and recorded within the Veeam Backup & Replication configuration database.
The ISO for Cumulative Update releases, indicated by a P in the build number, contain the initial version's installer and the cumulative update patcher. When this ISO is used to install, it first deploys the initial GA build of that version of Veeam Backup & Replication, and then as a post-install action, runs the cumulative update patcher. For example, running the installer for the 126.96.36.1997 P20210525 ISO would first install 188.8.131.527, then run the cumulative update patch P20210525.
The cumulative updates may include changes to the configuration database that the base version installer is not compatible with and causes the base version installer to fail when run.