For the past few weeks Delta has been unable to book otherwise-available business class seats on Air France. That’s been true systemwide, and their only advice is to try to find Delta flights instead. Good luck with that (even if Delta serves your planned destination, Air France business class availability is generally good, Delta’s very much is not).
Delta Points notes that the Asian call centers for Skymiles are now able to book these awards again, even though US call centers won’t see the availability.
He suggests calling Hong Kong at 011 852 2810 4288. I’ve had good luck in the past with the Singapore call center, English is quite good: 011 65 6336 3371.
Ask them to waive the telephone booking fee because the award cannot be booked online, some folks have been successful with that, although as a matter of policy Delta doesn’t do that. Or create an itinerary on the website reserving any flight, put it on hold, then call to change the itinerary. When the agent sets it up, be on the website and ticket it there, you’ll avoid the phone booking fee that way.
International agents may set up the pricing shell with fuel surcharges because Delta generally charges those on Asia- or Europe-originating itineraries. If you’re originating from the US you may need to correct them.
It’s very strange indeed that an Asian point of sale can access Air France business class availability, but a US point of sale cannot. It’s one more mystery in the ongoing “IT glitch” that has been ongoing, with no accommodations from Delta or projected date for solution, that in the interim is simply saving the airline from cost of redemptions.