Outlook bug preventing users from adding Gmail accounts on iOS and Windows being looked into

Some Outlook users are facing a frustrating bug that prevents them from adding Gmail accounts on iOS and Windows devices. The issue has sparked confusion, with people reporting OAuth-related errors during setup. Microsoft is currently investigating the problem, but for now, there are some workarounds that might help.

The problem: OAuth error blocks Gmail setup

On iPhones and iPads, users encounter a message saying, “Microsoft apps & services wants additional access to your Google Account.” But right after pressing “Continue,” the process fails, showing a strange, unreadable file labeled “oauth2redirect (data – Zero KB).” Others reported being redirected to a blank page with a question mark. Here’s a screenshot a user shared:

Meanwhile, Windows users also face errors, such as being unable to sync Gmail accounts through Outlook’s POP/IMAP setup. Some receive a message saying, “We couldn’t log on to the incoming server,” or encounter sync failures for subscribed folders.

What’s going wrong?

Based on user discussions, it seems that the bug relates to how Outlook interacts with Google’s OAuth system, especially if certain browsers (like Chrome) are used during the authentication process. Additionally, in some cases, switching phones or reinstalling apps triggers these errors, which also affect users who transferred data to new devices or removed the default iOS Mail app.

Workarounds for iOS users

While going through the discussions and threads on the issue, I found a few workarounds suggested by users that seem to work for others as well. First, let’s check out a potential workaround shared by a Microsoft Agent on the official forums:

You can try removing the Microsoft services permissions from your Gmail account and then re-adding the account.

1. Sign in to your Google account on google.com.

2. Select your profile picture in the top corner and select Manage your Google Account.

3. On the left side menu, select Security.

4. Scroll down to Your connections to third-party apps & services and select Microsoft apps & services.

5. Locate Microsoft apps & services has some access to your Google Account and select See Details.

6. Under Access you’ve given to Microsoft apps & services, select Remove all access.

7. Select Confirm.

At least one user confirmed that this worked for them. Another potential fix is to reinstall the default iOS email app. Once reinstalled,  go to Settings > Apps > Mail, remove the Gmail configuration, and try setting up the account again in Outlook.

If that doesn’t work, you can also see if there’s an update available for the Outlook app. While checking the threads, I noticed that most users claim the issue is present on Outlook version 4.2439.2. However, there’s a newer update now available to version 4.2441.0. I’d suggest installing it and trying again. Multiple users have noted that they simply waited for a while and were able to get it to work.

Suggested fix for Windows users

For Windows, Microsoft suggests a workaround that involves resetting your Gmail access settings. You can remove Microsoft’s access to your Google account and try reconnecting it. For complete steps, follow Microsoft’s instructions here.

Microsoft’s response

Microsoft agents claim that the company is aware of the issue and is actively investigating it. However, the root cause is still unclear, and a permanent fix has not yet been released. For now, Microsoft’s support team recommends trying these workarounds or using an alternative email app while the issue is being resolved. This bug may be inconvenient, but these quick fixes should help you regain access. Have you tried any of these solutions? Let us know if one worked for you! As usual, we’ll keep tabs on the situation and will post an update if and when we have any further details to share.