saving Error with saving project with big schematic

[wartillthend 3]

___________________________________________
############################################################################################
FATAL ERROR in
action number 1
of  Step Event0
for object app:

string_length argument 1 incorrect type (undefined) expecting a String (YYGS)
############################################################################################
--------------------------------------------------------------------------------------------
called from - gml_Script_buffer_write_string (line 1)
called from - gml_Script_json_save_value (line 1)
called from - gml_Script_json_save_var (line 1)
called from - gml_Script_project_save_timeline (line 47)
called from - gml_Script_project_save_objects (line 1)
called from - gml_Script_project_save (line 21)
called from - gml_Script_action_toolbar_save (line 2)
called from - gml_Script_app_update_keyboard (line 33)
called from - gml_Script_app_event_step (line 17)
called from - gml_Object_app_Step_0 (line 0)
 

Im assuming its because of a schematic I have but im not sure.

[Nimi 8.3k]

Does the scenery have any banners in it?