I was testing DavitMasia Emitters (33) and when I loaded thunder and clicked on play I got this, and then the program was aborted:
___________________________________________
############################################################################################
FATAL ERROR in
action number 1
of Other Event: User Defined 0
for object objParticle:
lerp argument 1 incorrect type (undefined) expecting a Number (YYGR)
at gml_Object_objParticle_Other_10
############################################################################################
--------------------------------------------------------------------------------------------
stack frame is
gml_Object_objParticle_Other_10 (line -1)
called from - gml_Script_create_particle (line -1) - <unknown source line>
gml_Object_objParticle_Step_0