Game stuck when load a custom map called First CLU

[yyc12345]

Affected BML version:
All BML version since the publish of this issue.

Phenomenons:
Game load progressbar stuck at first stage. And the game start music(Misc_StartLevel.wav) played unexceptly.
I dropped BML and game load this map correctly.
I also try deleting almost objects in this map and only keep the skeleton of a basic level. It still can not be loaded.
I enabled <Debug?> in base.cmo but got nothing.
I disabled all BML mods and it still can't be loaded, only build-in mods existed. (BML build-in mod, not the build-in mods in release package).

Reproduce step:
Download attached files. Both of overwriting original level file and loading it with BML can reproduce this problem. I can't indicate where is the bug comes from. So I open this issue, otherwise I will open a PR to solve this problem
CL_1_-_First_CLUs_Level.zip
.