How do I fix this?

I am trying to get my game to run so I can test it however this happens every time I tried to test it. I'm guessing it has something to do with the Polygon Collision boxes I have set, but I don't know.

I can't see your message urls - try adding spaces at the beginning.

If you are using physics, make sure the points on an objects collision polygon are not overlapping.

I cant add URL's as I dont have enough rep, but the Collision Polygon don't overlap.

Do the cannonballs spawn far enough away from the cannon so the sprites aren't touching when it spawns initially?

What is happening when you get that error, or does that pop up as soon as you hit the play button?

Its pops up as soon as I hit the play button. and the cannonballs do spawn far enough away.

Without seeing your capx, it would be near impossible to answer correctly, please share..

If the message says collision polygons, check every polygon on every frame of every object to see if they are correct..

If objects are square or circular, it might be better to use bounding box or circle instead of polygon ( you can set this in the physics properties)

I can't share my capx due to me not having enough rep.