Failed to load package

Ive created a multiplayer environment with v4.9.2 and i have completed everything i want to do to it but i have hit a problem when joining from the server list. when i click play i can host on client 1 and it takes me to the game. when i join the hosted game from client 2 it just closes down both clients and the output log shows this:

TravelFailure: LoadMapFailure, Reason for Failure: ‘Failed to load package ‘/Game/ThirdPersonBP/Maps/UEDPIE_2_Wasteland’’. Shutting down PIE.

I don’t have a clue what this is and cant find an answer anywhere online. I’m a beginner at all of this so any help would be greatly appreciated with sorting this problem out.

Thanks.

BUMP******