Cannot convert value of type 'NSFetchRequest<NSFetchRequestResult>' to specified type 'NSFetchRequest<T>'

T.fetchRequest() returns a NSFetchRequest<NSFetchRequestResult>, you have to explicitly cast it to the specific NSFetchRequest<T>:

let fetchRequest = T.fetchRequest() as! NSFetchRequest<T>
let asyncFetchRequest = NSAsynchronousFetchRequest(fetchRequest: fetchRequest) { result in
    success(result.finalResult ?? [])
}

Try either one of these.

One: I experienced something similar in my project.

I found that there were problems with the auto generated headers of Core Data entities. Try deleting from:

/Users/**user**/Library/Developer/Xcode/DerivedData/**AppName**/Build/Intermediates/**AppName**/Debug-iphonesimulator/**AppName**.build/DerivedSources/CoreDataGenerated

then clean your project with command+shift+K

Then try building.

Two: Try using let fetchRequest = NSFetchRequest<T>(entityName: NSStringFromClass(T.self))

Swifty style of 2nd approach, works 100%:

let fetchRequest = NSFetchRequest<T>(entityName: String(describing: T.self))