Hi, nancyz,
I have the same problem and have tried the steps in the linked KB article.
Where it says
6. Power on the newly created Boot Camp virtual machine, verify it can boot up correctly
it does not boot up correctly and I get the issue with it deciding there is no OS installed, wether the SIP is enabled or disabled.
If I create an imported VM from the BC partition, that will boot fine (not sure if that's significant).