B4J Question MacStorePackager Issue "Not certificates found"

When I run Store Packager by JanPRO, I get the error "Not certificates found! (-12)".

I am running it on:

• MacOS (tested with version 10.14.4, Mojave)
• Java JDK (version 8 update 181)
  
• Xcode + Developer Tools (10.2.1)
• Store Packager (v. 1.0.1)
• I am not running a virtual machine

I tried using an earlier version of Xcode (v9) without success. Version 8 will not run on my Mac. I have confirmed that the two certificates are on the Apple Developer "Certificates, Identifier & Profiles" menu (Mac App Distribution and Mac Installer Distribution).