After upgrading or attempting connect to a 14.3 RU2 SEPM, the connection appears Healthy and later fails within minutes after saving the settings.
SEPM 14.3 RU2
Possible parsing error when retrieving saved "Group Inclusions".
This issue is fixed in Symantec Endpoint Protection 14.3 RU3. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.
If updating is not possible then please use the steps below as a temporary workaround.
Note: It is recommended to replace the file. Avoid renaming the file in the same directory since the server loads all the .jar files in "...\WEB-INF\lib" folder, which may not even fix the issue.
Please note that if you have multiple connected SEPM instances at a site (that is, the SEPM instances share a database), create a connection to only one SEPM per site in the EDR appliance console. If multiple SEPMs from the same site attempt to connect to the same Symantec EDR management platform, they compete for authentication credentials and might not operate properly.
See the section About configuring the connection to SEPM in the EDR documentation https://techdocs.broadcom.com/us/en/symantec-security-software/endpoint-security-and-management/endpoint-detection-and-response/4-6.html where it states this.
This same error could be seen if a second SEPM is configured that shares a database with a SEPM that is already configured in EDR.