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Marco was talking about the hotfix for the storage upgrader which was released on may 27th.

As you didn’t post here before could you please tell us what the error message says.
Also if you are not sure if update to 1.8.7 worked open the updater app again. It will tell you your current operating system. If you are not on 1.8.7 go to settings > developer options, tick “stay awake”, plug in your phone and try updating again.

PS: Someone else just confirmed that the storage upgrade fix works with 1.8.7 too, so do that if you didn’t already.