The search for the specific file name "Pobierz Wurst v6.13 MC1.12 OFPlik" indicates a request for the for Minecraft version 1.12.2. Wurst v6.13 was specifically released to add support for Minecraft 1.12.2 . Overview of Wurst v6.13
If downloaded as a .ZIP, you must extract the files rather than running them from inside the archive. Pobierz Wurst v6.13 MC1.12 OFPlik: Wurst-Client...
You can find the relevant version on the official Wurst website . The search for the specific file name "Pobierz Wurst v6
The installation process for Wurst 6 differs from modern versions: Pobierz Wurst v6.13 MC1.12 OFPlik: Wurst-Client...