For Google Workspace.

For Microsoft 365.

Question:

What is the possible cause for "Invalid username or password" when I have entered the correct Username and Password?

Answer:

The username for the login is case-sensitive at HENNGE access control.
Please confirm your input. 

*In the case no access history was found in the access log.

If the username you entered is different from registered one, no access logs are recorded. (In the case your username doesn't match, please see the example below.)

*In the case you have activated "Ignore the domain name of username".

If username has a domain name in it, after “@” is automatically deleted.

In the case your username has a domain name in it, username doesn't match and login error will occur.