Hello Jiri, thanks for posting.
Yes, ultimately I do want to be on NCM 7.3; but I can't go there directly from 5.5.1. I have to go through various steps in a specific sequence, as in this KB doc SolarWinds Knowledge Base :: Compatibility of SolarWinds Orion Products for Installation and Upgrade.
I think if I went to 7.3 as a fresh installation, I'd lose the integration with NPM (which also has to be upgraded in steps).
So I'm going through an upgrade path for NPM, NCM, and NTA, to bring them all up to supported versions.
( I'm expecting that, at some point in the process, I'll have to upgrade/migrate server version and hardware, as well. Bu t I'll address that when it becomes necessary!)
Thanks,
Dave