It give messages like wrong paper size why - Canon Imagerunner 1600 Copier. 16 Pages per Min. IR1600

I am assuming that you are able to use different sized paper in your copier so it could be that you have, for instance, A3 or A5 paper selected as your default, or you are copying a page aand do not have the right sized paper loaded for it. Check your settings and change paper size to that you want to use as an input or output size.

Go into settings and adjust to the paper size in use--normally a4