I've asked olympus about this, I frequently used to get card errors with my Kingmax and Sony 16gb cards both were uhs class 10 or class 1 cards which they said was due to the cards. I now use a Sandisk ultra which gets less frequent card errors but they still occur. Usually i get a card error and I just have to remove the card and put it back in, a few times in the past with the sony and kingmax card where I lost my data and it said "no picture" after putting the card back in and attempting to review images. None of these cards presented any problems in any other device. I've been to their service centre to have my em5 looked at and had the shutter replaced twice, each time I ask them to check the memory card problem but they say they can't find any issue and say it must be due to the card. I've also had the camera freeze up when turning it off, where the lcd screen stays on after I switch it off and turning it back on again has no effect, the only thing that works is removing the battery. This happens with my 12-50, 14-140 and 14mm, I don't currently own any other lens so I can't test against others. Oly service also doesn't seem to be able to replicate this and says it's likely to be a card issue. It's not a big deal for me but it's annoying as hell. I'd like to know from any others with these issues if they were able to find a remedy or if your local olympus service was able to help sort it out.