products link from within Virtuemart back office goes to 404 error

[Uglystick]

Evening all, since upgrading to 3.6.4 10187 I haven't been able to access my products configuration area from the administrator back office.

www.________.co.nz/administrator/index.php?option=com_virtuemart&view=product just throws a 404 error...

To be very honest, I'm still learning, so not sure the best way to either A - find the fault and fix it or B - downgrade back to older Virtuemart?

Does anyone have any thoughts? is there a log or something I need to get out of my site for you to help?

Thanks for your help!