The recent migration to xcode 10.1 broke builds for apps using the file chooser API. In order to use that API we need to make changes to the provisioning profile to include iCloud support. With the new version you must have a container associated with iCloud for this to work.
To fix this follow these steps:
Figure 1. iCloud Settings
Figure 2. Select the Container
Notice that this will only work with the default xcode 10.1 mode. It seems that the application loader now requires this as Apple no longer accepts binaries with xcode 9.2 that use the older approach (without containers).