star trails software stacking error

[Sprites]

I tried using star trails free stacking software and it seemed simple, i stacked three photos. Today when trying to add photos it would not add any pics to stack. Any idea what causes this or is it the joy of computers?   It also said input error, i tried jpd bmp tiff .........

[Sprites]

I tried using star trails free stacking software and it seemed simple, i stacked three photos. Today when trying to add photos it would not add any pics to stack. Any idea what causes this or is it the joy of computers?

could a mod delete this topic please, i have sorted the problem out now

thanks.