Look all these pros, who think of protection
Just open the NewGen, enable UMSWE, reopen NewGen again and open the map - simple dudes =)
As already said the problem is this custom script "Custom script: call CreateDestructableInLine(udg_STEEL_X1, udg_STEEL_Y1, udg_STEEL_X2, udg_STEEL_Y2, 'B01U')".
Well I don't know this function at all, but if it creates something in a line from point 1 to point 2, you simply can do it with a loop.
Edit: Ahh the lane is in the trigger Folder "D&D Triggers" under the comment line "Extra DM commands" and the "set boundary" trigger.
Edit 2: Yes just played some minutes and I know what this trigger does:
When you cast "set boundary" ability, you set point 1 where you targeted. When you cast the ability again while point 1 is active, you create point 2 and between these points something is created and the 2 points are deleted again.
- Yes you can fix this with a loop!