Users are reporting that dozens of iPhone and iPad apps went down, according to DownDetector.com, and initial investigations point to Facebook’s software development kit (SDK) as the probable cause. Many of the broken apps rely on SDK to manage user logins, The Verge reports.

“Earlier today, a code change triggered crashes for some iOS apps using the Facebook SDK,” a Facebook company spokesperson told The Post.  “We identified the issue quickly and resolved it. We apologize for any inconvenience.”

Facebook acknowledged the glitch immediately: “We are aware and investigating an increase in errors on the iOS SDK which is causing some apps to crash,” the social media giant wrote at 7 a.m. Friday in a post to its developer platform.

All iOS users, and not just those who use Facebook to log into certain apps, were impacted. Android users did not report being affected by the issue.

This isn’t the first time Facebook’s software has temporarily disabled large swaths of popular apps: On May 6, virtually the same problem also rendered a good deal of apps temporarily useless for much of the day.

The underlying issue in both instances is that Facebook has become entrenched in a great deal of apps by offering up its log-in services (the ability to log in using your Facebook profile instead of setting up an individual user account) in exchange for advertising and analytics, meaning its issues have a wider impact. Both users and developers are growing increasingly irritated with the social media platform and its faulty software as a result, The Verge reports.

“Facebook really pushes developers into installing their SDK, likely because they want the very rich data they can collect on those app’s users,” app developer Guilherme Rambo told the tech news site during the May crash. “The SDK is offered as a convenience for both developers and marketing teams, since it can also be used to track the conversions of ads run through Facebook.”