Been trying to resolve this issue myself, and wanted to report some progress.
I had
Intershipper and Standard Shipping turned on. Get to check out with ArtioSEF turned on, and the system kicks out the error above.
I turned Intershipper shipping module OFF in Virtuemart, and the checkout process works perfectly with ArtioSEF turned ON.
Digging deeper, it appears there is a bug in Virtuemart's Intershipper shipping module. Virtuemart forums seem to support that Virtuemart's Intershipper shipping module will be fixed in the next release.
Anyone have other advice?
Thanks.