I have the same problem, and I wrote the exact location where the (in my case) smash bros iso file is
here I have a picture
@leseratte could you help me and tell what the problem is?
Thanks, and sorry for the ping!
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi