The digital display keeps flashing a 6 or lower case b, but I can't locate anything in the owners manual about it. I thought it was weak batteries, so I replaced the batteries with new ones (unless my daughter took the new ones and put old ones in the open pack).

So ME50 users, any idea what it might be?

Oh, as a side note. In my early days here we discussed the fact that pedals and boxes don't have on and off switches and couldn't figure out why. Well, I didn't figure it out, but I am happy to report the ME50 has an on and off switch. Just that little bit of information that allows one to sleep better at night.