Symptom
IPS policy shows 'Snort3 is partially in sync with Snort 2' warning generating confusion on the system
Conditions
Snort upgrade from Snot 2 to Snort3
Workaround
Ignore warning since this should not affect Firepower and Snort functionalities.
Further Problem Description
There were a number of SO rules and built-in alerts (called preprocessor alerts in snort 2) that were not ported to snort 3 because they were no longer needed. This log alert is just telling that the old rules are no longer available. It is safe to ignore the warning message.