When trying to upgrade a v12.5.2 (12.50.10200.1790) agent to the new v12.6 agent getting an error.
Same thing for 12.5.1 (12.50.10128.1060) agents.
Failed to start the remote update process on agent.
Verifying signature of the package files... Done
Connecting to agent server on the agent... Stopping all jobs on the agent before beginning update operation...Done
Closing connection with the agent update server... Done
Opening connection with the agent... Done
Connecting to update server on the agent... Done
Checking if manager is installed on the agent... Done
Checking if agent is running any other updates... Done
Checking for free space on agent... Done
Stopping the update support service if it is running on the agent... Done
Attempt no. 1 : Upload and run the support service on the agent...
Attempt no. 2 : Upload and run the support service on the agent...
Attempt no. 3 : Upload and run the support service on the agent...
Failed to install updates on agent 'blape-ccs-appsr.blccs.local'
Error uploading and running update program on agent 'bl-ccs-appsr.blccs.local'
Error copying C:\Program Files (x86)\Symantec\CCS\Reporting and Analytics\DPS\AgentUpdate\PU\apu-12.60\windows\smime\esmupdat.exe to bl-ccs-appsr.blccs.local
error writing request to update server on bl-ccs-appsr.blccs.local
error writing data header to remote process
An established connection was aborted by the software in your host machine
From the agent side you would see something like this.
 [2022/11/09 07:48:07:066] [INFO] Update server: Stopping one process: Esmupdate.
 [2022/11/09 07:48:07:066] [NOTICE] Update server: Service 'Esmupdate' does not exists, hence no stop service required
 [2022/11/09 07:48:12:079] [INFO] Update server: copy binary file esmupdat.exe
 [2022/11/09 07:48:13:229] [ERROR] Update server: error:2107C080:PKCS7 routines:PKCS7_get0_signers:signer certificate not found
 [2022/11/09 07:48:13:230] [ERROR] Update server: Signature verification failed for file `C:\Program Files (x86)\Symantec\CCS\Reporting and Analytics\RU\Package\esmupdat.exe', error-code=-8
Release : CCS Infra Release 12.6.1
This is known and expected. CCS 12.6.1 APU has prerequisites for the agents to have a Hot Fix.
Due to, it has updated certificates, that are not compatible with older agents that have not had the Hot Fix for the new certificates applied.
2 Hot Fixes were released 1 for 12.5.x agents and 1 for 12.6.0 agents.
As per the 12.6.1 documentation:
NOTE: If the steps above do not work, then try the following highlighted extra steps.