Hi all, I've been playing with bytemaps (see the latest LuaMetaFun manual) and I have come across a problem when I create more than 15 bytemaps. This came about as part of a bigger project where I create a large bytemap and then make smaller bytemaps with the data from the large bytemap. I've made a MWE below %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \startMPpage i := 1; for x = 1 upto 5: for y := 1 upto 5: newbytemap i of (250,250,3); setbytemap i to (floor(uniformdeviate(255) + 1),floor(uniformdeviate(255) + 1),floor(uniformdeviate(255) + 1)); fill unitsquare xyscaled (250,250) shifted ((x) * 255, (y) *255) withbytemap i; i := i + 1; endfor; endfor; \stopMPpage %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% The MWE above is for a 5 X 5 grid of randomly generated colours and you can see that the last 10m squares are black. Changing x or y to 3 will give 15 coloured squares, but a 4 X 4 grid and above gives black squares above 15 coloured squares. I can't see anything wrong with the code so I'm wondering if it is a bug. Any advice would be gratefully received. I'm running the latest update on a mac mini M1. Thanks Best Wishes Keith