Yes, the issue has to do with the shell script that checks the license key.
I think the license key may need to be regenerated based on a change we have made to the bundle ID, but you'll have to confirm that.
I was able to build debug versions to my development iPad, but that no longer works either, and I noticed this issue after I switched to create a release version of the application.
The error message is shown below:
2017-07-10 14:03:57.935 licenseChecker[25445:113573] Trying to register key = 6e60d-c5d4a-6df69-060f5-d5f9c for id = $(PRODUCT_BUNDLE_IDENTIFIER)
2017-07-10 14:03:58.163 licenseChecker[25445:113573] License key checking failed. Please check your license key and bundleID. (BundleID is case-sensitive).