What about App Groups?

Hello.

I ran into a problem when creating Cocoa apps.
When i send get-request to my local server - i get next message in console:
[User Defaults] Failed to read values in CFPrefsPlistSource<0x6080000e6700> (Domain: com.apple.PowerManagement, User: kCFPreferencesAnyUser, ByHost: Yes, Container: (null)): accessing preferences outside an application's container requires user-preference-read or file-read-data sandbox access, detaching from cfprefsd
I try create App Groups in Capabilities. Nothing...
How can I fix it?
I use Vapor like a web-service.