A Microsoft file hosting and synchronization service.
Hello Hawk Li,
We understand the issue has affected your daily work. Very sorry for the inconvenience caused at your end.
@Mate Jak, thanks for sharing the solution!
As Mate shared, you may also try activating TLS 1.2 in internet settings and check if the error code 0x8004e4c3 still appears when you sign in OneDrive app.
We do find other users also shared that the OneDrive error code 0x8004e4c3 is related to that TLS 1.2 is not enabled on the computer, it causes OneDrive cannot connect to the cloud service.
You may refer to following steps:
1.Close OneDrive and all Office apps.
2.Open Control Panel > Network and Internet > click Internet Options.
In Advanced tab, scroll down and find TLS 1.0, TLS1.1, TLS1.2 make sure they are all selected. Apply and OK.
3.Restart your computer, test in OneDrive again.
Please do let us know if it works for you. We'll be glad to provide further help.
Thanks for your patience and understanding. Hope you are keeping safe and well!
Best Regards,
Tina