Hi there! Thank you very much for the compliments :D
If it’s a low end hardware, you might be limited on how much VRam you can access. Since Our Paint saves the canvas in the video memory, it can limit how big you can draw. However if you are not drawing absolutely huge, it should work just fine most of the time.
Could you tell me how much memory your machine has and also video memory (if you have a discrete video card)? I could try to implement a limit on internal resource allocation and make sure it will work stably.