I have no clue what this error is or how to get rid of it. Everytime I open the application it shows up.
I introduced that dialog back in 2012, for this ticket: https://sourceforge.net/p/heidisql/tickets/2958/
You should just re-save your session, so it gets the right net type option in your registry. That should silence the dialog for the next time you open HeidiSQL.
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