Since replying to my comment from kbin doesn't seem to work, I've signed up here to post a little update.
If your project has Use Physical Light Units enabled, lighting through GDScript and the RenderingServer isn't possible to do cleanly on stable builds. The enum used to set light intensity isn't bound, so you have use its integer value.
Since replying to my comment from kbin doesn't seem to work, I've signed up here to post a little update.
If your project has Use Physical Light Units enabled, lighting through GDScript and the RenderingServer isn't possible to do cleanly on stable builds. The enum used to set light intensity isn't bound, so you have use its integer value.
RenderingServer.light_set_param(light_RID, RenderingServer.LIGHT_PARAM_INTENSITY, 1500)Becomes
RenderingServer.light_set_param(light_RID, 20, 1500)