After installing an older version of the Symantec Endpoint Protection Linux agent (14.3 MP1 or earlier) when already running a newer version of the Symantec Endpoint Protection Linux agent (14.3 RU1 or later), the client shows as offline in the Symantec Endpoint Protection Manager and may become stable, including dropping SSH connections.
Linux client with an older Endpoint Protection for Linux Agent (14.2.X) installed over a newer one (Endpoint Protection for Linux with cafagent).
Running both versions of the Endpoint Protection for Linux Agent simultaneously is unsupported and may result in system instability.
Installing an older Endpoint Protection for Linux Agent on top of a newer Endpoint Protection for Linux Agent is not supported and may result in the Linux client to enter an unusable state. If you wish to downgrade to an older version of Endpoint Protection for Linux, you must uninstall the newer Endpoint Protection for Linux Agent first.