I'm trying to install patch file to fresh installation on Debian 13.
Because the ServiceDesk instance I need to migrate from a very old Windows to Linux is build 14300, I started with a fresh install of build 14205 (which is the closer to 14300).
Now when trying to install the update, I get the following error:

Signature does not match with any available certificates. Please import valid certificate or contact support.

The update log shows the following:

Sep 24, 2026 8:30:45 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] :


Sep 24, 2026 8:30:45 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Certificate Temporary directory created :: true
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Going to download certificate without proxy
Sep 24, 2026 8:30:46 PM  [com.zoho.tools.util.NetworkUtil]  [INFO] : Downloaded /opt/ManageEngine/ServiceDesk/Patch/certTempDir/ppmsigner_publickey.crt of size 2,570 bytes.
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Certificate downloaded without proxy true
Sep 24, 2026 8:30:46 PM  [com.zoho.tools.CertificateUtil]  [INFO] : Creating new Keystore at /opt/ManageEngine/ServiceDesk/conf/manageengine.keystore :: true
Sep 24, 2026 8:30:46 PM  [com.zoho.tools.CertificateUtil]  [INFO] : Certificate identified by alias 0890bb68-7150-4661-a1f3-0097cc8280f4 imported successfully
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Certificate imported with alias 0890bb68-7150-4661-a1f3-0097cc8280f4.
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.UpdateManagerUtil]  [INFO] : Creating audit directory :: /opt/ManageEngine/ServiceDesk/logs/audit :: true
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.UpdateManagerUtil]  [INFO] : Creating new audit file :: /opt/ManageEngine/ServiceDesk/logs/audit/um_audit.log :: true
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Going to delete the temperory folder where the certificate file was downloaded.
Sep 24, 2026 8:30:46 PM  [com.zoho.tools.util.FileUtil]  [INFO] : Deleted File/Folder Path(if it exists):: /opt/ManageEngine/ServiceDesk/Patch/certTempDir/ppmsigner_publickey.crt
Sep 24, 2026 8:30:46 PM  [com.zoho.tools.util.FileUtil]  [INFO] : Deleted File/Folder Path(if it exists):: /opt/ManageEngine/ServiceDesk/Patch/certTempDir
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Temperory folder where the certificate file was downloaded was deleted false
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : Invoking UpdateManager in CMD mode
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : UpdateManager ProductName: AdventNet ManageEngine ServiceDesk Plus
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : UpdateManager ProductVersion: 11.0.0
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManager]  [INFO] : UpdateManager ProductContext: SERVICEDESK
Sep 24, 2026 8:30:46 PM  [com.adventnet.tools.update.installer.UpdateManagerCMD]  [INFO] : The product directory:/opt/ManageEngine/ServiceDesk
Sep 24, 2026 8:31:03 PM  [com.adventnet.tools.update.installer.PatchIntegrityVerifier]  [SEVERE] : Signature does not match with any available certificates.

My procedure is:
- Download https://www.manageengine.com/certificate/ppmsigner_publickey.crt to /usr/src
- Download https://updates.manageengine.com/certificates/latest.crt to /usr/src

- Run: sh UpdateManager.sh -c
- Option c to import /usr/src/ppmsigner_publickey.crt
- Option i to Install
- Enter /usr/src/latest.crt when required (also tried using ppmsigner_publickey.crt)

Please advise.

Thanks!