[Mod/AGE] Modifying some Effects cause mod not being able to load

Age of Empires II: DE II - Modding
1

I have created a data mod by copying the original .dat file and edit using AGE3, and have some issue in which the game refuse to load my mod.

This cause the game to reject my mod (“Error: Problem loading data”, log file says “presence data missing”):

  • Add a new Tech, empty or not
  • Add a new Effect, empty or not
  • Modify existing Effect in a certain way: Set attr 44 (Blast Attack Level) to 2 and attr 22 (Blast Width) to 2 for class 52 (Tower), in Murder Holes effect

However, in Loom effect I have Set attr 44 to 2 and attr 22 to 2 for class 4 (Civilians), and the game accept this.

Can anyone tell me what have I done wrong? I am sure I didn’t delete or overwrite anything important.