After the Update to 2.0.0p1 you may face this issue, while trying to activate changes
Please check the web.log inside the Site directory (~/var/log/web.log). You will receive a message, that the hard link cannot be created.
/omd/sites/master/var/check_mk/site_configs/fe/local: b"cp: cannot create hard link
to '/omd/sites/master/local/share/check_mk/agents/custom/my_mrpe_plugins/bin/check_http_ntlm': Operation not permitted\n"
You might want to add the command to fix it:
chown <sitename.> /PATH/of/the/hardlink
The activate changes should run now without problems.