The errors, you have, are from missing DirectX. You will need to install DirectX 10 or higher.
Or
You can also try opening UE4PrereqSetup_x64.exe which will install all prerequisite for the game. You can find it in:
IragonBETA\Engine\Extras\Redist\en-us\UE4PrereqSetup_x64.exe
I hope this fixes your problem!