Futuremark has had manufacturers, usually of handheld mobile equipment, cheat by programming their video to recognize a 3dMark test and run it in an unusually optimized way. As a result they now check drivers to be sure that their tests are run in the same way as normal operation. With Nvidia and AMD graphics cards, "Not approved" almost always means the driver is so new that Futuremark hasn't got around to checking it yet. For Vega, I suspect a new driver is the case and it will be approved in a week or two.
Ruinz, that's quite a rig and heavy on the graphics. According to the details on the Futuremark page, you are using stock speed and turbo with the 6700K, XMP DRAM, and stock speeds with the Vega cards. Good choices for a new build -- overclock it later. Reported CPU and DRAM speeds are as expected. GPU core clock looks good, but I haven't seen a Firestrike run with a graphics memory bus clock that low. Maybe it's the right speed for VEGA and AMD's newer memories, but check it out. What tool - hardware or software - are you using to adjust graphics board clocks and/or voltages?
Another suggestion is to use GPU-Z to check that the PCIe bus is at PCIe-3 and using the right number of lanes during the run. A two-card graphic rig and 6700K should use 8 lanes to each card. AMD crossfire uses that bus for communication between boards as well as from CPU to graphics.