I did see a similar discussion on 'dropped a tcp packet with no matching session' but it didn't match my problem, and I already tried their suggestion. Since upgrading from 7.0.1 to 8.12 my RDP users have been getting disconnected during their remote session and cannot reconnect to our network until I reboot the firewall. They work fine for an hour or so then get dropped. When they try to reconnect we're seeing the log entry 'dropped a tcp packet with no matching session'. Regardless of what we try I cannot get them reconnected without rebooting the firewall. I've tried modifying the Application Defense settings but it didn't help. I do have a trouble ticket open with McAfee (3-1616898306) but it's unresolved. I had to fall back to an older model firewall running 7.0.1 and management isn't happy. They're inquiring about purchasing Cisco firewalls but I've got a lot of experience working with the Sidewinder and want to keep them. Any suggestions?
This could be a session limit problem.
Check all the application defenses in regards to TCP timeouts.
For to me unknown reasons the default for most of them is 3600 seconds - cut them down to the 120-300 seconds and see if that helps.