Have you tried creating a separate folder to extract the markings into?
I also researched to why this might be happening and the possible reasons why are here:
CRC error while extracting the downloaded RAR file
RAR file corruption caused due to virus infection
Bad sectors on storage media is another cause for RAR file corruption
Interruptions during uploading or downloading RAR files
Try going into control panel\\WinRAR then right click WinRAR in the list of programs and select uninstall/change. If it asks you if you want to repair it, try it.