Complex sentence: Reviewers had been sent a Steam download code to play the game while waiting for their console versions to arrive in the mail and upon attempting to launch the co-op mode, players were given the error message Could not join.
Split into simpler sentences: Reviewers had been sent a Steam download code to play the game while waiting for their console versions to arrive in the mail. Upon attempting to launch the co-op mode, players were given the error message Could not join.