According to MSI Support on your CPU, your Motherboard's Compatibility Chart on the BIOS version it needs to have installed is version 7B09v1B for your Ryzen 2950X CPU to work. Support For X399 GAMING PRO CARBON AC | Motherboard - The world leader in motherboard design | MSI Global
RYZEN Threadripper Colfax SP3r2 YD295XA8UGAAF 2950X 100 3.5 8MB 32MB B2 180 N/A 7B09v1B.zip
I looked at MSI BIOS and Driver download and the version that your CPU needs is the latest Version of BIOS MSI offers for your Motherboard. Support For X399 GAMING PRO CARBON AC | Motherboard - The world leader in motherboard design | MSI Global
- Update AGESA Code 188.8.131.52A
- Enhanced Game Boost function.Note1. Please power off your system for once after BIOS is updated.
2. Please make sure that windows has been updated to the latest version.Version
- Update AGESA Code 184.108.40.206B.
- Improve USB mouse compatibility.
- Support 2nd Gen AMD Ryzen™ Threadripper™ Processor.
So, If your Motherboard was manufactured after 08/14/2018 then it should have the correct BIOS installed for your 2950X CPU.
Check the box and see if it lists the BIOS version of the Motherboard you have.