Currently, attempting to edit a picture whose ID is null or negative triggers an error in EasyRPG, the same goes for vehicle commands tied to parallel processes (like those in #3565).
As those invalid picture ID errors could very well just be ignored, which would not lead to a crash of the Player just after, I think they could be turned into warnings without affecting developer experience on making a game.
For the vehicle command, it may be trickier, as I do not know if it fully a fatal error or not.
Currently, attempting to edit a picture whose ID is null or negative triggers an error in EasyRPG, the same goes for vehicle commands tied to parallel processes (like those in #3565).
As those invalid picture ID errors could very well just be ignored, which would not lead to a crash of the Player just after, I think they could be turned into warnings without affecting developer experience on making a game.
For the vehicle command, it may be trickier, as I do not know if it fully a fatal error or not.