Error code

Riot Unknown DirectX error

RIOTUnknown DirectX error
Game/Platform Error· An error code shown by a game or gaming platform/launcher.

What it means

A DirectX error prevents the League client from launching.

How to fix it

  1. Update your graphics drivers.
  2. delete the game.cfg file.
  3. relaunch the client.

Not affiliated with Riot. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.