I have subscribed to the Windows Phone Preview for Developers program. I have attempted to update but, my phone is telling me that there are no more updates available. My OS version is 8.10.12397.895.
According to WP Central, the OS is a much higher number than mine, therefore I should be able to update.
The article I am referring to is here: http://www.windowscentral.com/critical-update-available-those-windows-phone-preview-developer-program