Joomla/VirtueMart: Debug the product detail page

after migrating virtuemart and joomla to the last version the product detail page is not working, i get a 500 error, if i check the discounted price only then the page work it's an urgent project so pls. don't bid if you haven't got enough time (max. 1 days). If you have questions pls. don't hesitate to ask, i'll provide all the infos u need. !!! IMPORTANT !!! Please don't give a quote if you don't have enough capacity, the project should begin immediately. Please don't give a quote if you're not interested, in many cases i got quotes and when i'm writing i don't get a response, for this kind of freelancers i think they quoted blind w/o any interested. Project rules: 1- Payment would be escrowed fully at the begin, after finishing the whole project i'll release pls. dont ask during your work for release 2- a testserver would be provide 3- The given and accepted time is the dateline if the candidate couldn't do the job in this time and don't inform me in-time the job would be cancel 4- i would be informed frequently about the progress 5- It's not allowed publishing this work in private portfolio or elsewhere and sharing this 6- All parts of programming should be commented and a little tutorial/documentation should be written afterwards