There might be a lot of reasons but incorrect installation is the most frequent.
However there are additional complications in some cases.
If you are on macOS 10.13 (High Sierra), please reboot your computer. When you copy a new Audio Unit (or a new version thereof) to the Audio Unit folder under High Sierra, no host will see it until you reboot your computer.
If you purchased Panagement Enterprise Edition and still see the previous Free Edition, please check that you have copied your plug-in from the Panagement EE archive, not the Panagement FE archive. The similar names often create confusion.
Pro Tools subscription does not support the same set of plug-ins than a regular Pro Tools. Please check with the Free versions before purchasing.
In other cases, contact us by email and we'll sort it out.