Error 8018830f downloading Windows Phone 8.1 Update 1 - we have a solution and Joe Belfiore is investigating

There are increasing reports of the new Windows Phone 8.1 Update 1 failing to install on some phones.

It throws up error 8018830f with the message "The update was downloaded, but couldn't be opened".

There are several possible reasons, including not enough internal storage space and low battery. But it's still being reported even when these reasons have been eliminated.

We had the same problem on a Nokia Lumia 625, which had been on 8.1 Developer Preview and was updated to 8.1/Cyan in the first wave of updates before Microsoft put a block on them forcing users to downgrade to WP8 and update again.

We solved the problem by doing just that with our Lumia 625. We downgraded to WP8 using Nokia Software Recovery Tool and then updated over-the-air to 8.1/Cyan. Here's how.

We then installed and activated the Preview for Developers app and updated successfully to WP8.1/Cyan Update 1.

And after that's all done, just hard reset your phone - Settings > About > Reset Your Phone and restore it with a back up.

Give it a go.

Update: Windows Phone software boss Joe Belfiore has acknowledged the problem and says it's being investigated:

We're not so cure it's a "very small %" but at least Microsoft is looking into it. Judging by feedback, our solution above appears to work for the Lumia 925 and the Lumia 625.