Homebrew Pizza Worm trouble

[TeconMoon]

I downloaded Pizza Worm and tried it on my new R4DS, and the rom loads, but then on the bottom screen it says, "fatInit ERROR"

I then tried with DSorganize.

I tried the chishm loader, which apparently freezes.

I then try with Mighty Max. It starts with, "Initializing FAT."

Then in a little bit it goes to,

"Interface: DLDI
Please wait, booting your file.

For some reason, the file was not loadable."

What am I doing wrong? I've played this before on slot-2 solutions.