astropixel processor help

[graham.hobart]

Hi folks, I have downloaded a trial copy of APP and whilst I like it I have run into an issue. I was just trying to stack LRGB fits-
I integrated the separate channels successfully and ended up with some stacks, but when I try and add channels in the tools/combine RGB i get a file size not compatible message -despite me using the same routine for each file.
Help please-there seems to be two files -a fits. and an ST.fits version in the list.
Graham

[The_bluester]

The .fit and st.fit is the difference between a file that you have applied a stretch to before saving and an unstretched one. All the letters and numbers in the APP saved file names tell you what processes were applied like LNC, multi band blending, drizzle etc.