I get the 888/1E.1 on my iTaste v3 sometimes. It continues to work, though. I asked the question to the vendor and they didn't know either.
I got this error message twice, only 5 minutes ago, on my iTaste v3. It is the new version with rivets all over the place.
It happened mid-vape. It seems like the unit reboots; At least the puff counter resets. Right now the unit seems to work fine.
I have had earlier experiences with my iTaste turning itself off mid-vape, but I didn't notice any error message those times.
Edit to add: I just emailed Innokin support and asked them what these codes mean.
Edit to add II: After topping up the battery, it happend again. I hope Innokin answers soon.
Edit to add III: I got the error message yet again, and this time I switched to a different clearo. Since then there haven't been any more error messages/reboots. I'm beginning to suspect that this error message/reboot thing simply means that the atty is shorting. Keeping my fingers crossed.