Verify the username and password are correct
Reset the password if needed
Check that Caps Lock is off
Confirm the account is not locked, disabled, or expired
Ensure the authentication server is online
Check network connectivity
Verify the correct domain, tenant, or environment is selected
Clear browser cache and cookies
Try a different browser or device
Re-enter or refresh the authentication token
Check that multi-factor authentication is set up correctly
Sync the device time and date
Remove and re-add saved credentials
Update the application or client
Review recent password changes or policy updates
Check for account permission issues
Disable VPN or proxy temporarily
Contact the system administrator or support team