when using the mobile version of SevenZipCompressor, exceptions are thrown if there are no events handlers for events Compressing and CompressionFinished.
 

Solution :

Add the following code :
 

       if (handler != null)

 
to common.cs :
 
internal void OnEvent<T>(EventHandler<T> handler, T e, bool synchronous) where T : System.EventArgs

    {
        try
        {
            if (handler != null)      <-- add this line !
                handler(this, e);