theme no longer working on phones and tablets

Hi. i purchased a theme from you guys a few months ago. it has been working perfectly and all of a sudden now it won't load on tablets or phones... my pictures and menu bar don't show and my product category links i created just show up as text. what needs to be done to fix this?? the only plug in i don't have updated is the visual composer bc its saying i need to purchase a product license.. is that the problem? (i didn't think it would be because its needed updating for a little while and the phones and tablets were working fine still. or did i do something? i don't believe i deleted anything that shouldn't have been.. please please help i am opening my business in 2 weeks and am slightly freaking out! only thing i have personally added in terms of codes is a code for a subscribe form and that was only on a couple pages and that is working just fine! just want to know what i need to do on my end to get my site working properly on phones and tablets bc i know a lot of people do their shopping via phones and tablets!
thank you!
-megan