Error: Unknown Service Class – SonicWall Posted on by Webmaster IT Support Forum › Forums › Network & Firewall › SonicWALL › Troubleshooting › Error: Unknown Service Class – SonicWall Tagged: NAT Policies This topic has 0 replies, 1 voice, and was last updated 2 years, 8 months ago by Webmaster. Viewing 0 reply threads Author Posts September 24, 2020 at 10:25 am #2427 WebmasterKeymaster You may get the following error when changing the NAT Policies in SonicWall: Error: Unknown service class This may be because you are trying to set a group of services to translate into a single service. Author Posts Viewing 0 reply threads You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In