When using unrealpak to make a patch, if the source pak data that a patch is based from is encrypted, you must specify the "patchcryptokeys" parameter on the command line so unrealpak knows which crypto.json file to use to access that source pak file. The editor doesn't add those parameters, nor does it offer any way of configuring that.
We should add the crypto.json for a build into the release version data, and then have UAT find that and pass it to unrealpak with the "-patchcryptokeys=" parameter