Windows Phone 8.1: stuck in spinning wheels problem?
The Windows Phone 8.1 Update 1 should ideally run smoothly. However, under certain circumstances the update might be stuck at a pair of spinning wheels with a bar that possibly doesn't move after several minutes.
If that happens, in order to solve the problem, all you have to do is remove the SD Card, then press an hold the power button and then once the phone is restarted you should immediately see how the bar below the spinning wheels will start moving. Depending on the phone you have it might take more time but certainly it should start moving and the installation should continue without any further hassle.
We have tried this with the Nokia Lumia 625, Lumia 1520 and Lumia 1320 and worked perfectly well.
If you have a different model and this also worked for you, please, let us know in the comments below!
UPDATE 01/JAN/2015: Users from CyberCultura have reported that this workaround also solved the problem with the Windows Phone update 8.10.14219.341 in the following models: Nokia Lumia 720, Nokia Lumia 810 and Nokia Lumia 520. Thank you all for letting us know!