Earlier this week many folks began experiencing an issue where macOS Mojave 10.14.4 could not properly log in to some Gmail-based accounts, mostly those using G-Suite for custom domains. The good news is that, as of late last night, this problem appears to have been eradicated.
Our best guess is that this was a Google-originated problem, at least this week. Here’s the timeline that leads us to this conclusion:
- January, 2019 – Early in the 10.14.4 betas, developers and other beta testers reported having this exact issue. It then went away, though it’s hard to tell if Apple took any specific action to fix it.
- Monday, March 25, 2019 – macOS Mojave 10.14.4 was released. Anyone updating on this day had no issues.
- Tuesday, March 26, 2019 – Folks began having the aforementioned authentication loop/fail issue and were unable to retrieve mail with macOS Mail.app from some Gmail accounts. A few also reported issues with iOS, though reports on that were spotty, at best.
- Also on Tuesday, March 26, 2019 – Google announced they rolled out some changes to G-Suite authentication. These primarily talk about changes to two-factor authentication while the bug affected folks with and without that, but the timing is too coincidental to ignore.
- Tues-Friday, 3/26-3/29/2019 – The web blows up about the issue, folks are scrambling trying to sort out various solutions and workarounds. One of these fixes involved using Charles, a piece of proxy software, to intentionally play a “man-in-the-middle attack” on your Mac, inserting itself as Google’s authentication servers, passing back a piece of information that was missing from Google’s own response.
- Late-night, Friday, 3/29/2019 – The problem simply goes away, seemingly without Apple having made any changes to macOS on anyone’s Macs.
Adding together the timing of when the issue started, Google’s G-Suite authentication announcement, the method by which the “Charles workaround” worked, and the timing of the solution, our interpretation is that Google fixed the issue on their servers last night and now all seems to be well for everyone from whom we’ve heard. And ourselves. Our long, international nightmare is now over.