Now, additional information is transmitted between Switch and SwitchClient which results in the following compatibility issues.
Switch 09 and SwitchClient 10:
This combination is not supported. A newer SwitchClient should always to talk to a Switch of at least the same version. Attempting to connect to an older Switch returns an error during connection.
Switch 10 and SwitchClient 09:
This combination is supported. The communication protocol is adjusted in such a way that an older client still gets the information it expects. This is helpful when users have upgraded PowerSwitch and cannot ensure to upgrade all SwitchClient installations at the exact same time.