Resolved: Skype and MS Teams blocked by Ultrasurf signature
03/26/2020 59 6117
Skype, MS Teams, Slack and other applications may be blocked by SID 6855 - PROXY-ACCESS Ultrasurf.
A new signature was released to block Ultrasurf but this is impacting other applications.
Update as of 7/4/19 2:30 pm EST: The signature (SID 6855) has been removed from the Ultrasurf application. If you continue to experience issues with blocked apps/websites please update the App Control database by logging into the firewall and navigating to MANAGE | Rules | App Control and click Update.
Disable the Ultrasurf Signature Under Proxy-Access category Signature ID: 6855 should make the impacted applications working again.
- Navigate to Manage | Rules | App Control
- Lookup for SID 6855
- Change the block setting to Disable
Please see the following product notification for further updates: Service Impact Notification for Firewalls Using App Control