Link doesnt work, suddently!

hi today i noticed that i have not been able to open the form link. what seems to be the problem? I have customers who can open and submit their orders but some couldnt.

please help. I am using the paid version

https://secure.jotform.me/form/51997994672479

I have tested the link and I'm able to access it without any issues, do you receive any errors when you attempt to access the link?

I have done my tests in  chrome, FF and opera. I have also cleared you account's form cache, please let us know if the issue persists