Recently I encountered an error while creating web application from central admin site
"The password supplied with the username was not correct. Verify that it was entered correctly and try again".
The reason is that administrative password may have been modified but SharePoint farm is still using the old administrative credential.
To fix this issue execute below stsadm command:
stsadm -o updatefarmcredentials -userlogin <domain\username> -password <newpassword>
