Warning
Your Virtuemart installation contains an error: No user is marked as vendor. Please fix this in your phpMyAdmin and set #__virtuemart_vmusers.user_is_vendor = 1 and #__virtuemart_vmusers.virtuemart_vendor_id = 1 to one of your administrator users.
Check in virtuemart tools & migration, you have a Set vendor field. Enter the user id from the administrator, save it and it should work