-MacOs Catalina viene con permisos extendidos: se requiere intervencion del usuario para acceder a carpetas Documents, Downloads, Desktop, etc

En el Info.plist le agregué:

<key>NSDesktopFolderUsageDescription</key>
<string>To be able to load user files from Desktop folder</string>
<key>NSDocumentsFolderUsageDescription</key>
<string>To be able to load user files from Documents folder but also load and save configuration</string>
<key>NSDownloadsFolderUsageDescription</key>
<string>To be able to load user files from Downloads folder</string>



-para probar reset permisos carpetas mac, para que los vuelva a pedir al usuario:
tccutil reset SystemPolicyDocumentsFolder com.cesarhernandez.zesarux
tccutil reset SystemPolicyDownloadsFolder com.cesarhernandez.zesarux
tccutil reset SystemPolicyDesktopFolder com.cesarhernandez.zesarux
