Solved:
The Wiki pages nowhere state that the Access-key and the serial-Number should NOT use the spaces that you can see in the Android Nefit App, or on the underside of the Nefit Thermostate.
When I Copied the Number and Key from the App into the startupline in the NefitEasyHTTPserver.sh I got ...

Please also check the github issues of nefit ease server. Did you check the openssl setting of your RPi?
https://github.com/robertklep/nefit-easy-http-server/issues/35#issuecomment-510818042


hi Walter, Thanx for your reply,
Ik have made a new issue : https://github.com/robertklep/nefit-easy ...

I am one step further: PM2 now only starts up the nefithttpserver once (as it should, no more restarts), and in the logs there are no more errors, only that Easy-server is online. so it looks like this part is ok.
I have disabled IPv6, and I edited the Hosts file where i removed the IPv6 entries
I ...

I have installed the Nefit easy-server, following all the steps in the wiki. working with Pi4.
Easy-server did not start.
I did update all parts of the installation and also the OS
assured the ssl security was adjusted.
the PM2 start proces stops the process after to many restarts.
I started the ...