I saw a question about converting Softplan 2014 to PDF.

This may work as it works for Softplan Version 14.

Download Cute PDF Writer, it's free.

Select your drawing in Softplan, PDF Writer becomes one of your printer selections.

Select Print in Softplan, when your printer screen comes up, do not select "Print to File". 

Select Cute PDF Writer and select Print, I get a PDF file everytime.