Framework init param is not a member type of class

I am working on one framework and it is working fine if it is directly connected to the test app in the same project. But when I build it for release and implement it into another test app it shows me this error:

Failed to build module 'MySDK' for importation due to the errors above; the textual interface may be broken by project issues or a compiler bug

After some digging, I get an error message

 ... is not a member type of class ... 

And the problem is in the initial parameter and in my observer this is my entry / init class:

public class MySdk {
...
    public init(eventObserver: MyResultObserver){ // this observer is a problem maker
        EventObserver.shared.attach(eventObserver)
    };
 
    public init(){}
...

and this is how my MyResultObserver looks like (it is in a separate file)

import Foundation

public protocol WalleePaymenResultObserver: AnyObject {

  func success(successMessage: String)
  func error(errorMessage: String)
}

and extension:

import Foundation
extension MyResultObserver: NSCopying {

    func copy(with zone: NSZone? = nil) -> Any {
        return self
    }
}

How should it work (it is working in a test project in that SDK folder)

import UIKit
import MySdk


class ViewController: UIViewController, MyResultObserver { // added observer here 
    func success(successMessage: String) {} // observer function 1
    
    func error(errorMessage: String) {} // observer function 2

...
    
    @IBAction func openSdkClick(){
        let myAwesomeSdk = MySDK(eventObserver: self) // init my sdk with observer 
    }
    
}

But the problem is when I implement it like this into the test app (as cocoa pod) it will give me an error above. I try to remove this observer parameter and SDK works fine. How can I make my observer visible? Should I put it into headers somewhere? any hint?

Framework init param is not a member type of class
 
 
Q