the java script is not working well on my site so i would like to disable the one page checkout.
is it possible to disable it?

No it is not possible to disable it. All checkout logic was remade in new version 4.2.
 
Regards,
ViArt Support

on previous version i had custom fields like order notes in the checkout process. so how do i add a special field now? most of the orders need a note to the seller

Order notes still work fine...

thanks