NickCat said:
The "lazy" was more referring to QC on the firmware by obviously not testing the update on enough different body/scenarios to ensure it would work. I do realize they can't test every scenario though, but a body with registered batteries seems like a fairly common one.
But, yes... I see new body firmwares coming soon!
I don't think it's happening to every body with battery information registered; my 5d3 has battery info registered and the STM upgrade went through first try. But it is clearly happening to some combination of battery, body and battery information registration. I wouldn't rule out an unforeseen interaction between some custom setting and the battery registration.
I haven't been following this closely enough, but I wonder if maybe the issue is with battery information registered from counterfeit or third party batteries? Maybe the people who had the issue and then succeeded after deleting the battery registration information can chime in on that.