Checkout not working

hi
please have a look here
https://edeltruhe.de/warenkorb
"warenkorb" / checkout doesn't work, if I click on it, I come to start page.
If I use core template, the checkout is working fine.
I use joomla 3.7.5.
when I would buy the newest update from this template, is it ready for this version? in the details is written "compatibility: 3.6".
thank you for your help.
when I will buy templates "all themes" is it for life time?
regards
grit

Hi

I'm afraid Shop and Buy did not get the latest VM updates due to its age. Try rename /html/com_virtuemart in template to something else to check if override is not causing it.