(I also opened this bug at redhat bugzilla but afterwards it looks like this is not used anymore for freeipa? - so i open it here as well)
Using the "Change Password" in the Dropdown of the webui to change the password to one that includes a german umlaut (äüö) will make it impossible to login again on the webui. Login with the new password in ldap or via cli kinit still works.
krb5kdc says: " PREAUTH_FAILED: user@REALM for krbtgt/REALM@REALM, Incorrect password in encrypted challenge"
Resetting the Password via the admin and then change password via "Your password has expired. Please enter a new password." Prompt will lead to a working webui but you can not login at any other place (ldap, kinit). Also you can not change your password anymore "2100: ACIError"
No Login possible anymore on the webui, login in ldap is still possible.
Login possible with new Password
ipa-server-4.6.6-11.el7.centos.x86_64 ipa-client-4.6.6-11.el7.centos.x86_64 389-ds-base-1.3.10.1-5.el7.x86_64 pki-ca-10.5.17-6.el7.noarch krb5-server-1.15.1-46.el7.x86_64
If you use the cli tool to change the password to one with a umlaut everything works except for the webui.
Metadata Update from @rcritten: - Custom field rhbz adjusted to https://bugzilla.redhat.com/show_bug.cgi?id=1865884
Issue linked to Bugzilla: Bug 1865884