OpenId Connect defines the return variable names in case of error. It requires error and error_description. We used to use error_code instead, before, so we now need to support both 'error' and 'error_code'.
Targeting to 4.2. Do we need it also on 4.1.z?
No, OpenId is just for 4.2.
Verified with: ovirt-engine-4.2.1.1-0.1.el7.noarch {"error_description":"Cannot authenticate user 'admin@internal': The username or password is incorrect..","error":"access_denied"}%
This bugzilla is included in oVirt 4.2.0 release, published on Dec 20th 2017. Since the problem described in this bug report should be resolved in oVirt 4.2.0 release, published on Dec 20th 2017, it has been closed with a resolution of CURRENT RELEASE. If the solution does not work for you, please open a new bug report.