This error occurs on Nagios 2024R1.1.3 when it has been upgraded from a previous version that had been using the Neptune Theme.
Some of our customers have been able to overcome this issue by simply clearing their cache and session tokens on their browsers. If the issue persists, you can reset the user theme to the modern using the following mysql query (change THEPASSWORD to the correct password you are using for the nagiosxi user. The password for your nagiosxi user can be found by running the get_mysql_passwords.sh script on the command line of your xi server as root: /usr/local/nagiosxi/scripts/get_mysql_passwords.sh).
Command to run to change user theme to Modern:
mysql -unagiosxi -pTHEPASSWORD nagiosxi -e "update xi_usermeta set keyvalue = 'xi5dark' where keyname = 'theme' and keyvalue = 'neptune';"
We have also observed that performing the upgrade to 2024R1.1.3 (upgrade 2024R1.1.3 to 2024R1.1.3) a second time, using the command line , may resolve the issue:
Nagios xi - Upgrade Instructions for Nagios xi 2024
Nagios is also treating this issue as a bug and will try to address it in future releases. Please monitor our changelog for updates:
https://www.nagios.com/changelog/#nagios-xi