My phone is stuck at 99% after i restarted

[Martine1977]

What can i do . I tried restarting my phone and its stop at 99% for the last hour now

[YoGem]

@Christofer I suppose that the 99% is the app optimization and that may be related to the MM upgrade that it's said it force full encryption.

If all I am saying is correct, which I am sure it is, unless Sony disabled the default encryption (see my note at the end of this comment) the high wait time is due the fact that the setup is encrypting the storage. Hence, if that is the case.. Connect the device to the charger and wait. It may take a very loooooong time to complete.

Note: Marshmallow encrypt the storage by default however this can be skipped following Google guidelines that state that if a device is a low end one and/or with not enough ram (less of 2gb I guess) and SD/Internal storage has a low r/w speed (below 50mb/seconds) OEMs will be able to disable encryption, not otherwise. Meaning that I am quite sure that the M4 startup delay may be related to storage encryption. 

[Christofer]

@YoGem As far as I know encryption isn't required for devices that are updated to Android 6.0 from a previous version of Android.

[YoGem]

Christofer, I confirm that what you say is absolutely correct. So at this point unless the devices were already encrypted and the new apps need to be encrypted, thus taking time to complete the initial boot after the upgrade, I have no idea why the first boot is taking all this time!