Logon to Salesforce fails with error message "Your login attempt has failed. The username or password may be incorrect, or your location or login time may be restricted. Please contact the administrator at your company for help."

Problem:

Logon to Salesforce fails with this error message:

"Your login attempt has failed. The username or password may be incorrect, or your location or login time may be restricted. Please contact the administrator at your company for help."

Resolution:

The users browser shortcut is likely pointing to a weird URL, but should be just https://login.salesforce.com/
Removing everying after the slash ("/") should fix the problem.