"controller init failed" when attempting to read ECM, 2003 Mustang

Hey guys, like the title says, I'm attempting to read this ECM for the first time. After it prompts me to turn the ignition off for 3 seconds and then back on, I get the error "controller init failed". I'm using MPVI2+ and it's got the latest update. Any ideas?

I?ve got the same problem on a vehicle, pulled file just fine, sent to write file and getting this error..
Hate these damn 99-04 mustangs, should have just told the guy no