Your 17 word post may have seemed descriptive when you typed it, but it doesn't really contain enough information to allow us to give you a decent answer.
You should include your specs (eg. ArchiCAD/PlotMaker versions, hardware, etc) in you signature (Djordje?). And you should give a better description of your situation - then you'll get better help.
Nevertheless you can probably fix your problem by going to the PDF Converter folder in your ArchiCAD folder and running the install.exe again. Then run ArchiCAD/PlotMaker again.
Cheers,
Link.