MM issue
 

Can someone let me know why one day my MM was running like a beast on 4s and today it will recognize 4s but it will not go with it. All I get is a solid red LED. It recognizes and runs on two and three but not four. Could this be from the updated firmware. I updated my controllers on yesterday so could that be the cause. Let me know. Thanks.

I'd say yes the firmware did it. Only way to be sure is to revert to an older update, then try it again. I ran my MM 2 years straight on 4S, no issues.

4s again...
 

I updated the firmware and bam...back online with 4s. Thanks Red.

the reason it did that was because castle added overvoltage protection to their new software. this new feature is most likely to protect 2 battery setups that were meant to be wired in parallel, but a series adapter was accidentally used instead.