Dapper now uses MacOS built in Music access in order to get access to your libraries.
Unfortunately for larger libraries of over 1TB or more, the process of Dapper asking MacOS to "Give me access to the library" is extremely slow.
I added a warning to users noting that larger (1TB/2TB or more) libraries should stick to “Audiophile mode” using XML files and not direct music access since Apple’s built in method for access libraries of this size is very very slow and will make Dapper look like its “Application not responding” while it gets the data from MacOS.
If you have a large library, press and hold down the option key at startup… select “No” to debugging, “No” to resetting and “Yes - XML Files Mode” to using Audiophile Mode: