Unfortunately I have been experiencing the following error on my Lumia 520 trying to update to Windows Phone 8.1 Update 1:
Can't update phone It's a probably a temporary problem. To try again, go to Settings > Phone Update. (0x80188308).
I haven’t seen any resolution to this issue so far as so I decided to simply back up my data and then do a hard reset:
- From the Start Screen swipe down and tap All Settings. Scroll down and then tap About and then tap reset your phone and follow the prompts.
After the reset log into the Preview for Developers and then go to All Settings, Phone update and Check for Updates.
After this I found that Update 1 installed correctly – current OS version: 8.10.14157.200.
Note: Off the top of my head I don’t recall how much phone storage is required to complete an update but I had over 3.5 Gb available after the update was complete.