@Galunid I honestly can't remember. I think I disliked v2.3 for some reason an reverted to v2.1.2. However, maybe v2.3.1 came out... I seem to remember having to rename the xxxxxxx-update.upx file to update.upx only, before it worked. However, we're talking about thing I might have done in May. I know for sure that I took a lot of precautions before upgrading. I don't know whether had to I use them.
(I did also get the partitions backup, radical_update, system, boot, recovery, vendor, kernel and resource from 2.2.2. So if you've rooted the device, you can reflash them and then reupgrade to whatever version.)