Error code

Xbox E101

XBOXE101
Game/Platform Error· An error code shown by a game or gaming platform/launcher.

What it means

The console encountered an error while applying a system update..

How to fix it

  1. Perform an Offline System Update using the OSU1 file on an NTFS USB.
  2. ensure $SystemUpdate folder is at the USB root and not nested.
  3. contact Xbox Support if hardware is suspected.

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