suspicious cast there is no type in the solution which is inherited from both

I should cast one class into Generic Interface because of some requirements. But I am having ReSharper warning "suspicious cast there is no type in the solution which is inherited from both". In run time, it cause run time error.

I should do this because I am using reflection so I desperetly need this cast. My code as below. Any support appreceated.

ScreenShot below

namespace ConsoleB2B

{

public interface IEntitySubMultiLang
{
    int Id { get; set; }
}

public interface IRepo<TEntity> where TEntity : class, IEntitySubMultiLang
{
    void Add(TEntity item);
}

public class GenericRepo<TEntity> : IRepo<TEntity> where TEntity : class, IEntitySubMultiLang
{
    public void Add(TEntity item)
    {

    }
}

public class Entry: IEntitySubMultiLang
{
    public int Id { get; set; }
}

public class Class1
{
    // Error occurs in this line
    IRepo<IEntitySubMultiLang> _r = (IRepo<IEntitySubMultiLang>)new GenericRepo<Entry>();

}

}

ScreenShot