Sth. keep still running after File downloaded

Hi,

I have create a HtmlElement table in Custom Screen linked to Sale Section Tab to list some special Documents of current Sale. It works fine.

User select one Document and click Button to download this file in background. The Implementation to this Button for Download works also.

The Problem is, after File downloaded it's  still running sth. in Background so that the Page keeps still endless inactive.

Does someone has same Experience what's runnning here and How I can fix?

Many Thanks!