Adding a new dropdown in propertyGroups

[thuren.machine]

I am trying to add a new dropdown in the propertyGroups section of postsData.json file but each time I open the post processor dialog from within Fusion, my changes disappear form the json file. I've been able to add a new dropdown via the cps file defining a different group but I am still  curious why these changes disappear from the json file? 

[viacheslav.shapilov · Accepted solution]

You should not touch this json file. It is used as an interrogation cache to improve performance. If you want to add new post property to a post, add it to the post cps file.