Users are reporting that their NBA 2K18 save files have been corrupted on Nintendo Switch.
According to user reports, the save file becomes corrupted when the game tries to connect to the server with Flight Mode enabled. It’s best to keep Flight Mode off when playing NBA 2K18 during this point of time.
This isn’t only happening on the Switch version of the game, as players on the PS4 and Xbox One version have reported similar problems.
A patch for this issue is on the way and will be distributed in the near future.