Some DX11 errors reported on this forum have been traced back to hardware errors: bad DRAM (specifically, DRAM that was no longer getting a good connection the MB, which was fixed by re-seating the DRAM) and an overheating CPU (fixed by cleaning the heat sink) for example.

On PCs, there are free hardware diagnostics you can use to check your system.
PassMark Software's Memtest86 and BurnInTest, for example.