cannot make PNG have transparent background

[Anonymous]

so i have some PNG files which i have used in previous archicad files which have a transparent background cars people plants etc for presentation.
and in the past these have worked fine in v20 and im pretty sure in ver 21 also but for some reason they are showing up with a black background now in my AC21.
and no amount of selecting the transparent tickbox makes any difference to the image so it retains its black background instead of transparent. what is the deal here?

[Anonymous]

ok after some investigation i have discovered that if i want a transparent background i can no longer use the file>merge command anymore which is strange as this worked fine for me previously

instead i need to use file>external content>place external drawing then enable transparency

seems to be another bug that you are unable to make transparent a file that has been merged in??

[Laszlo Nagy]

Can you upload one of those PNG files here?

[Anonymous]

I would upload but I have not since been able to replicate the problem in 2 different AC files since unfortunately. perhaps my AC/ comp just needed a restart?