Even after following this guide, you might fail. Here is why:
If the watermark was added as a stamp via another PDF program: master pdf editor remove watermark
of Master PDF Editor, watermarks from the unregistered version (e.g., “Created with Master PDF Editor”) can be legally removed by purchasing a license key. Once registered, the software no longer adds watermarks to saved files. Even after following this guide, you might fail
If you use the unregistered version to save or export a PDF, it will automatically add a "Master PDF Editor" watermark to every page. Even after following this guide