- Scenario: Upgrade from KepServerEX V6.11 to Thinkgworx Kepware Server V 6.16.217
- Issue: After migration, Siemens S7 Plus Ethernet driver does not load. Error message in Event Log: Unable to load driver DLL: C:\Program Files (x86)\Kepware\KEPServerEX6\drivers\siemens_s7_plus_ethernet.dll.After checking the digital signature of the dll, the certificate in the signature cannot be verified.

- Solution: There are 2 "dll" associated with the Siemens S7 Plus Ethernet Plus drivers:
- AGLink40.DLL
- siemens_s7_plus_ethernet.dll
Try to find on another PC/Server the certificate from the dll "AGLink40.DLL" with a "digital signature OK", then export this certificate and import it onto your server.

Reinitialize TKS, that's it that's all.
But Best Practice, when migrating from KepServerEX to Thingworx Kepware Server:
- Backup your configuration
- uninstall KepServerEX
- Install Thingworx Kepware Server