Hey GranadaExp2,
Are you using wired or wifi internet connection ?
I went that link to x, which is talking about OneDrive, but should not be related to a successful log in. I really have no idea whether it does or doesn’t but from looking at hundreds of posts my opinion is that OneDrive only interferes with saved projects if they’re saved in a folder OneDrive is backing up, not the actual logging in of UEFN.
UEFN projects are usually saved in User/Documents/Fortnite Projects, if OneDrive is enabled for Document folder Backup, you can set a different folder to one that Onedrive doesn’t backup, like C:\Fortnite Projects in UEFN editor preferences.
I get this error once every few days, but second attempt always logs in… if your internet is not wifi, then it should be working for you… unless your not authorised… do you have a profile in the creator portal ?