A "Permission Failure" error typically means you didn't sign-in to Apple iCloud on the device you are using to run your app. That includes running on iDevice Simulator. The fix is to go to the device's "Settings" and log-in to iCloud. Once this is done, you shoud be able to run your app on that device without getting Permission Failure. Not sure what happens if you use the new Apple Authentication code (circa Fall 2019). Perhaps that would also eliminate the problem from occuring. iCloud doesn't let a User write to CloudKit unless they have an Apple ID and are logged-in to that ID. Typicallly your phone will be logged-in, but when using Simulator prolly not!

ok, but you didn't explain the procedure you used to "add the index". So this isn't helpful. Nowhere in the CloudKit dashboard (circa Fall 2019) is there a navigable area to "make the recordName queryable". ???

In either you simulator or your iDevice, go to settings and sign-in to Apple's iCloud. Users are not allowed to write (CREATE) to CloudKit databases unless signed-in. Signing-in, via Settings, will get rid of 10/2007 "Permission Failure" "CREATE...." error.

On your simulator or you iPhone, go to setting and sign-in to iCloud. Users are not allowed to WRITE (CREATE) records to CloudKit unless they are signed-in to Apple iCloud. This is what causes this Permission Error. Apple should obviously add more color to their error; it shouldn't be so hard for devs to debug it (but it is).

What does this mean Spok?Schema? Security Rules? What? Where are these things?

Yes, and no one can find the answer bc Apple forums ROT.

It's really really sad that this problem has a high search ranking on Google, and yet remains unanswered by Apple or anyone else.Also having this error, and ZERO luck finding the answer. This problem listed here is 4 years old.. crickets. Come'on Apple, ***?