I'm having the checksum issue as well. I'm using the Snes9x 1.6 emu and all is ok with it when i run games outside of LB, but when opening the game through LB it tells me that i have a checksum problem and the rom is corrupt.
Ok .. i took some more time to watch some youtube vids and found that typing *.* in the File name box once you get to the folder your invisible exe is in and hitting enter will sort the above issue out.