We have finally resolved the issue. To help Unreal beginners who might experience the same warning message, sharing the solution here.
Issue:
When adding FMOD sound to Niagara, a critical message appears saying the FMOD module failed to load, causing Unreal Engine to either force quit or crash with an error message.
Reproduction:
This issue occurs only when a Niagara effect with FMOD sound is played through a Blueprint.
Cause:
It is caused by the incorrect order of initialization and module loading in the Unreal subsystem.
Solution:
Rearrange the initialization order of the Blueprint and FMOD modules during Unreal’s startup.