Affected people will find their tablet asking to be plugged into iTunes, but unable to be restored, a number of support forum posters have said. Ireland's The Journal noted that this can be accompanied by an "Error 56" message, which Apple identifies as a generic hardware error.
While the issue appears to be restricted to iPad Pros, there also seems to be no immediate workaround other than taking a device to an Apple Store for help or a replacement. There are likewise no signs that an official fix is in development, though Apple is likely aware of the problem.
iOS 9.3.2, released on Tuesday, was itself intended to solve a variety of bugs. These included things like Bluetooth problems on the iPhone SE, failed dictionary lookups, and MDM servers being unable to install custom B2B apps.
Because the iPad Pro is a relatively new device — even the 12.9-inch model only dates back to November — every owner is still on Apple's default one-year warranty, and should be able to get free service for defects.