I'm currently trying to make which transitions to another map when it is complete. I'm not using an elevator and the logic_script is currently triggered by a trigger_look which occurs during the map.

I've followed the instructions on the level design wiki exactly and have checked over them numerous times but whenever it reaches the point in the map where the script entity is triggered nothing happens and I get a message in the top left of the screen saying "Cannot run script: NULL script name". I've been looking for quite a while and I can't seem to find any help.

Any suggestions about how to fix it?

Is this a mappack? Or a mod? If it's a mappack, a simple point_clientcommand with an input of Command > map [mapname] you can "cheat" and load up the next map as if you went through console. Combine with an env_fade and nobody will know!

Can't you just use a changelevel trigger?