I was also seeing "There's no information available for In-App Purchases. Try again later." 21105 [Environment: Sandbox] and deleting then reinstalling through Test Flight didn't seem to make a difference at all. I'm not sure which part of this finally got things to work, but things seem to not throw an error now. When I went into Setting -> [Apple ID Section] -> iTunes & App Store then at the bottom saw that I had setup a different apple ID as the Sandbox Account than what I was logged into my device with. I went ahead and changed my beta test app to just be open to anyone with a link rather than using a specific account and changed the Sanbox Account in that menu to be the user that the device was logged in with and now things are working.