Google Chrome icon on smartphone - Chrome 79 update bug

Update: December 18, 2019 at 1:13 p.m. ET: A Google spokesperson reached out to Android Authority to give some background on the Chrome issues from the M79 release. The M79 update was suspended after Google detected the WebView issue, and all app data will be made visible again after the fix rolls out later this week.

The full quote can be found below:

The M79 update to Chrome and WebView on Android devices was suspended after detecting an issue in WebView where some users’ app data was not visible within those apps. This app data was not lost and will be made visible in apps when we deliver an update this week. We apologize for any inconvenience.

Google tells Android Authority that the Chrome issue only affected Android users that were included in the initial M79 update rollout. The company stopped the update before it reached 15% of users, not 50% as was originally reported in our initial story.

Google will be pushing out this Chrome fix directly, so developers shouldn’t need to take any action to get things fixed.


Original article: December 16, 2019 at 6:30 a.m. ET: Last week, Google rolled out the Chrome 79 update for Android smartphones with multiple security improvements. Google is now pausing that update thanks to a bug that’s deleting user data from some apps.

As reported by 9to5Google on Friday, apps that rely on Android’s built-in WebView have been affected by the bug. Developers noticed that their apps started losing data after people updated Chrome to version 79, thereby updating WebView also to version 79. Some devs even called this a “catastrophe” and a “major issue.”

For end-users, apps seemed like they’d been reset or downloaded from scratch. Saved data reportedly disappeared and some were even logged out of the apps.

Google has now acknowledged that Chrome 79 is indeed responsible for this data loss in apps. The company says it’s working towards a fix and has paused the rollout of the update. However, a reported 50% of users have already downloaded the new browser version.

Google wrote the following on the Chromium blog:

We are currently discussing the correct strategy for resolving this issue which will be one of:

a) continue the migration, moving the missed files into their new locations.

b) revert the change by moving migrated files to their old locations.

We will let you know which of these two options have been chosen soon. In the meantime it would be good to collect a list of affected packages, and details of whether any mitigations have been released to users, and in what versions so that we can test that the respin doesn’t interact badly with the mitigation.

Although Google addresses the bug, it says that the new changes were made to WebView in beta six weeks ago. “Had the issue been picked up at that point we would have been able to address it before it significantly impacted users,” the company notes.

How did a Chrome update result in app data loss?

On Android, Chrome is responsible for rendering a webpage inside an app. So when you login through a webpage inside an app, it’s Chrome’s job to load the content. As reported by some developers, Chrome 79 updated the location where this web data is stored. Some say there was a problem in data migration. So apps that rely on WebView or run inside WebView entirely experienced data losses.

However, the loss of app data is not irreversible. As Android Police points out, Chrome hasn’t deleted the data after the migration, it’s just not accessible right now.

There is no word yet on a list of affected apps or by when the lost user data will be restored. We’ll update this post when we know more.

Have you recently noticed missing app data or random app log-outs after updating to Chrome 79? If yes, drop us a line in the comments section below.