In version PRTG16.2.23.3270, trying to start the PRTG core service results in the message "sorry, could not start prtg core server (web server)"
There is no known issue in regard to the service start in version 16.2.23.3270 in general.
Log onto the system that runs the PRTG core server and open the PRTG Administrator Tool. Please try to start the core server service from the Service Start / Stop tab.
Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.