There is a known error that occurs after upgrading CSM from 1.4 to CSM 1.5.0 and later. This error is shown when looking at users in Keycloak’s web UI. The error occurs due to a change in how the LDAP configuration is done in earlier versions of Keycloak. This should not occur on fresh installs. The error occurs when looking at the user lists on Keycloak Web UI, and once looking at the page leaves a error message on the page stating “Cannot read properties of undefined (reading 0)”
To recover from this situation, perform the following procedure.
After seeing the error page you will need to refresh the page and ensure you are on the correct realm again
Go to the User Federation section
Click on the LDAP configuration page
Click on the switch before Enabled to disable the LDAP configuration
Click on Disable on the pop-up to disable the configuration
Click on the switch again to enable the LDAP configuration