@DM72
Try these little tricks to avoid common errors when logging in.
Clear your system cache and cookies first.
Open an incognito tab, then try logging in again.
When logging in from a system/ device that remembers your login credentials, allow the system to automatically log you in as opposed to tapping sign in button.
I have noticed that once the credentials auto fill, the system may try to automatically log you in and if you tap the sign in button at the same time it may produce a 'sign in error message'.