First off, Welcome to SEN!
Secondly, your problem is your map dimensions (184 x 84). If both of the sides are not a standard dimension (64, 128, 192, 256), then the game will crash for players (unless you play another map before playing it).
To elaborate on the second statement: If you play a normal game first, and then play your map, you won't crash. My guess is that when you were testing with your friend, it was the first map you were playing on SC, but he had played at least another map before joining your game. That is why he didn't crash when you did. To fix this problem, make one of your map dimensions a standard dimension, or always remember to play another map before playing this one.
To change map dimensions in SCMDraft 2:
1. Click "Scenario" in the file menu.
2. Click "Map Dimensions" in the drop-down (first option).
3. Change the width or height of the map and click the "Resize / Change Tileset" button.
This will add null tiles if you make the map larger, which you can cover with more terrain. If you make it smaller, it will cut out the existing terrain.
Hope this helps!