Inconsistency: possible bug in win32 version 713 build 137
My son (user:chrizztopher) for some reason uses the legacy version of TPT.
When I open his save "secret message!!..." (691188) https://powdertoy.co.uk/Browse/View.html?ID=691188 with the normal version of TPT, it behaves differently depending on which version of TPT is used: specifically, the photons reflect from the first wall at a different angle; this means that the whole thing doesn't work in proper TPT.
More important than the failure of this particular sim is the difference in behaviour, which seems to be readily reproducible: start both powder.exe and powder-legacy.exe, then open and start 691188 with both.
strangebeing