I recently downloaded FFXIV after a few months of not playing and now I can't run it because of this DX error: A fatal DirectX error has occurred.(100000000)

Comp Specs
Pentium i7
2x AMD R9 270x GPUs
16Gb RAM
4.5TB HDD
Windows 8.1 64 bit

I have no hardware errors and DXDiag says nothing is amiss.