CheckMK broken after update from 1.5.0p9 to 1.6.0p6

Hello everyone,

after updating CheckMK the site is not working anymore, although it starts up without an error. It seems like nagios configuration is broken.

OMD[master]:~$ cmk --debug -R
Generating configuration for core (type nagios)…OK
Validating Nagios configuration…ERROR:
Traceback (most recent call last):
File “/omd/sites/master/bin/cmk”, line 94, in
exit_status =, mode_args, opts, args)
File “/omd/sites/master/lib/python/cmk_base/modes/”, line 72, in call
return mode.handler_function(*handler_args)
File “/omd/sites/master/lib/python/cmk_base/modes/”, line 1143, in mode_restart
File “/omd/sites/master/lib/python/cmk_base/”, line 99, in do_restart
if config.monitoring_core == “cmc” or cmk_base.nagios_utils.do_check_nagiosconfig():
File “/omd/sites/master/lib/python/cmk_base/”, line 48, in do_check_nagiosconfig
cmk_base.console.output(stdout, stderr)
File “/omd/sites/master/lib/python/cmk_base/”, line 47, in output
text = text % args
TypeError: not all arguments converted during string formatting

The web GUI shows this: Cannot connect to ‘unix:/omd/sites/master/tmp/run/live’: [Errno 2] No such file or directory

Can someone tell me what went wrong here? I could not find a solution so far

Greetings and thanks in advance,

Problem solved - the core was set to icinga, after changing it to nagios it worked again.
The current options for core are “none” and “nagios”. Is Icinga not going to be an option as a checkmk-core in the future? Icinga2 is also not available and I am simply curious why it is not offered anymore as a core option.
I am asking because we inherited some rather complicated shell scripts from a previous admin which only work with the icinga core. (I learned this when updating from 1.2 to 1.4 some time ago)
It seems that our two options are now either to rewrite the script - probably as much work as writing it new - or using a different tool to generate reports. Any recommendations?

Icinga 1 got removed as option because it is EOL.
I do not think they will integrate icinga2.
You have to convert the scipts for nagios or take over the features of those scripts into cmk checks/plugins that are independent from the (nagios) core.