...
Log on via SSH and become site user. Then do (one step after another):
Stop the site
Code Block language bash theme RDark OMD[mysite]:~$ omd stop
.
Reload the config
Code Block language bash theme RDark OMD[mysite]:~$ cmk -O
.
Start the site again
Code Block language bash theme RDark OMD[mysite]:~$ omd start
...