This can happen sometimes if you used the yourdomain.com/login method to access your Dashboard.
My Website Solutions are super conscious about security and protecting your website from the nasties that try and break in to steal your data - you will probably be surprised to hear that we battle 100's, sometimes 1000's of these nasties each day, and do it gladly to keep your data safe.
One way to combat them is to only allow logins from your dedicated Dashboard login page.
The positive side of this is that on the second attempt to login you are highly likely to gain access to your Dashboard. Have you given this ago?
TIP: once logged in to your Dashboard, bookmark the page so next time you can login with ease.