(credit: Microsoft)

Microsoft’s Windows Insider program suffered an awkward setback last night as the company released two different builds—one for desktop users, another for mobile—without apparently meaning to.

In both cases, systems configured to use the fast ring could find themselves downloading and installing Windows releases that weren’t supposed to ship to the general public. For desktop users, the problem is merely an annoyance; the build, taken from a development branch named “RS_EDGE_CASE,” appears to work, broadly speaking, but “may include issues that impact usability of your PC.” Such issues aren’t entirely uncommon on the fast ring, though this time Microsoft warns that such problems may be more numerous than usual. Anyone who installed the build can either roll back to the previous release or wait until Microsoft publishes a new fast ring build. That will happen next week at the earliest, as the company has said it won’t be publishing any new builds this week.

The mobile situation is a little more grave. Again, a build was released from a different development branch—this one named “RS_IoT,” denoting that it’s not even a mobile build at all but rather an Internet-of-Things variant. Unlike the errant desktop build, this build isn’t usable; phones that install it will get stuck in a boot loop, and the only way to restore them is to use the Windows Device Recovery Tool. This will wipe the entire phone and flash it with a working firmware.