The issue you linked was cause by an ad blocker. Try using a fresh browser (or private mode with all extensions disabled) and try again. We’ve also seen software like McAfee Web Gateway to cause same issue by blocking some of the browser’s POST request.
I have tried in mozilla without any extension and apparently the error persists, also I tried in private mode. anytime I click in sign in or sign out it shows the error
In that tab, open (or refresh) NXRM and reproduce the issue
Right click the table and “Save all as HAR with content”
Share the resulting file with us, if you want to keep it private, please open a ticket at https://issues.sonatype.org/ under “Dev - Nexus Repo (NEXUS)” project
Thanks for filing the issue. Until we release the fix a workaround would be an admin logging into NXRM and going through the on-boarding wizard and after clicking “Finish” button it should be fine for anyone to log into NXRM. We are sorry for the inconvenience.