I'm sending my app to testers with Beta from Crashlytics which is an amazing tool to do app testing.
I had every new tester's device UDID registered in my developer account and then distribute a new build.
My testers got email invitation and accessed app's installation which could not be completed on their device. They kept seeing an alert showing up with message:
Unable to download app - MyApp could not be installed at this time - Done / Retry
Testers' testing status are "installed" in my Crashlytics dashboard but they're actually not able to finish installation.
Please help me find any possible factor causing this problem.