After login to my dashboard all I read is… "error"

Hello,
When I try to get access to my WP dashboard through my PC I can’t login… All I see is a plain text message saying “error”.

It’s like I was banned from my own site though I can’t get howcome it is possible.

I just succesfully logged in by means of the WP app for iPhone under 3G (not wi-fi) because I wanted to avoid using the same IP address we all share at home. I’d like to add I’ve whitelisted my IP address on the .htacces so I have no idea what’s wrong.

I’d accept some suggestions since I’m running out of clues.
Thank you in advance!