In a main view use the key combo Ctrl+Shift+U and select "Reset Program Settings". Close and reopen RM9. Then go to Publish>FamilySearch Central and see if you can login. FamilySearch's FT API does not currently support two-factor verification. If you have that turned on with FamilySearch you will need to remove it. The FT API also supports limited special characters, some characters may cause a login issue.

If you are still unable to login temporarily turn off your firewall, anti-virus and internet filtering software to see if one of them is blocking RM9 access to the internet. Then adjust their settings.