Hi All, I have LHR to DXB booked in Economy Flex. I would like to either pay cash to upgrade, or apply Skyward Miles.

When I try to request an upgrade on the Emirates site, it says "Unfortunately this segment cannot be upgraded."

Anyone have any experience doing this? I understand that LHR levies additional taxes if you fly in a premium class, so am I restricted from doing this online? Also, any timeline on when business class availability opens up?

Thanks!