Exception in Custom Action during RollBack

In custom action I override following function and got exception in rollback case...

"savedState dictionary does not contain the expected values and might have been corrupted. "

Is there any other way to rollback ?

   protected override void OnBeforeInstall(System.Collections.IDictionary savedState)
    {            
        try
        {                

            bool report = false; //Some validation
            if (!report)                
                throw new InstallException("License is not valid.");
            base.OnBeforeInstall(savedState);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            base.Rollback(savedState);
        }

    开发者_如何学C}

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Change "base.Rollback()" in the exception handler to "throw;". Your caller will call Rollback at the correct time.

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You can use pinvoke to call the cancel button on the base installer. This will rollback without any installexception error message dialogs.