Sophos certificate error || 0365 error

Hi SatyabrataB,

Thank you for reaching out to Sophos Community.

This would not fall under the firewall for the isolation part, as you've stated that the issue is removed upon removing Endpoint protection. I'll be moving the following query to Endpoint Forum.

Also, to verify, are the core agents updated? 

https://docs.sophos.com/releasenotes/index.html?productGroupID=esg&productID=sesc_core&versionID=allVersions

Hi SatyabrataB ,

Good day.

Thanks for reaching out to the Sophos Community Forum.  

Since you mentioned that removing the Sophos endpoint resolves the issue, Can you please test with basic troubleshooting steps to identify which Sophos component triggered this issue?  

Also, please ensure the Sophos agent is updated with the latest version.

Additionally, you could refer to this thread whether it’s due to firewall rules. 

Dear Yogalakshmi,

firewall rule i have checked everything is allowed i cannot follow basic troubleshooting steps because its not showing all the time.

what i observed after i installed endpoint ssl certificate changed to sophos endpoint certificate that time its shows certificate error.

if i uninstalled endpoint same device and same network its not showing any error.

Hi SatyabrataB ,

Good day.

Can you please try checking this article whether the exceptions mentioned here are added to allow Office 365 installation, updates, and general usage through the Web Protection module of Sophos Firewall.

The exceptions fix the timeout, antivirus errors, and HTTPS inspection issues.

Dear Yogalakshmi,

I was added in exception.

what i observed today in case a user machine disconnects or switch LAN to WIFI that time it is showing error.

I have added those certificates to trusted but no luck.

Thanks

SATYA