I've reached Secretas and no enemies are spawning, even after waiting almost an hour (I have a couple of platform polluting).

I don't know if it is related but if I try to force them to spawn with the editor the game partially crashes with this error:

Error while running event FTL-Ships::on_built_entity (ID 6)
FTL-Ships/script/FTLSCRIPT.lua:11: attempt to index local 'burner' (a nil value)
stack traceback:
FTL-Ships/script/FTLSCRIPT.lua:11: in function 'get_speed_boost'
FTL-Ships/script/FTLSCRIPT.lua:26: in function 'new'
FTL-Ships/script/FTLSCRIPT.lua:76: in function 'handler'
core/lualib/event_handler.lua:72: in function <core/lualib/event_handler.lua:70>

Never seen that error when I was spawning in new enemies.

100% going to be some odd mod interaction, I need to know what mods are adding to that spawner and the enemies. Or a save.

Sadly I have MANY mods.. the biggest ones are:
Paracelin
Arig
Rubia
Secreta&Frozeta
Vesta
AAI Industry
Alien Biomes
Arachnids
Armoured Biters
Cerys
Explosive Biters
Frost Biters
Maraxis
Moshine
Outer Rim
Panglia
Toxic Biters

I uploaded the save in my gdrive -> https://drive.google.com/file/d/16vm-YCwPXnIU_y8D5YE86VHKsSc0NXx9/view?usp=sharing

Alien biomes is enemy #1 for space age playthroughs, it just breaks a lot of things.

I'll try to disable it

Damn, it doesn't seem to be it

I see what is happening, can't fix it right this moment but will be on it.

Halfway into a fix, no ETA.

Happy to see that they finally spawn! Thank you so much!