When my client changes the order status or searches in the order page it redirects him to the main Joomla Control panel and does not actually change the status. He seems to be the only one with this issue. I have checked in all his browsers and also deleted cache etc.
Any thoughts on why this would happen?
http://forum.virtuemart.net/index.php?topic=79799.0
Is the client registered as Vendor?
does it happens if you use order-status-change with the all-orders-overview or with using order-details-view in BE?
disable vmdebug and joomla debug. Then it may work. if not, increase Ram and similar