Why my form is not allowing multiple submissions?

Hello, i´m confused because i create a Form really good, yesterday works perfectly, but today appear a message: 

This is because the option to allow only one submission per user is enabled:

You should set this option to "No Check" in order to allow multiple submissions, I mean, users will be able to submit the form more than once. 

Here is also a guide that will provide you more details about this: How-to-Set-Unique-Submissions-on-a-Form

Hope this helps. 

Perfect i fix it ¡

Thank you very much, the Forms are great