Same problem here. Xcode 12.5 Getting pretty annoyed with how poorly the tools work for Apple Watch apps. Debugging is also horrible.

I tried a 7.0 simulator and it didn't work. When I check the pairing in the iOS simulator I get the 'Syncing not complete" and it never does. I'm appalled by how horrible the Apple Watch development experience is. I never want to make a watch app again.

How can the accepted answer be the accepted answer? That's insane. Please tell us what fixed it.

Same here... just upgraded to Xcode 13 and it's stuck on this, 8714/8802 files. Is there really no solution?

I somehow found a way around this. I closed any open projects, I created a new project (iOS App), got that project to build, then the issue kind of sorted itself out the next time I opened the project that was giving me problems. I don't know if this will work for you, but something to try anyway.

I added this extension to make it a more or less identical API signature: extension NSKeyedUnarchiver { static func insecureUnarchivedObject<DecodedObjectType>( ofClass cls: DecodedObjectType.Type, from data: Data ) throws -> DecodedObjectType? where DecodedObjectType : NSObject, DecodedObjectType : NSCoding { let unarchiver = try NSKeyedUnarchiver.init(forReadingFrom: data) unarchiver.requiresSecureCoding = false let decodedType = unarchiver.decodeObject(forKey: NSKeyedArchiveRootObjectKey) as? DecodedObjectType return decodedType } }