If WinRAR or 7-Zip reports a "Checksum error" or "Unexpected end of archive" specifically at part13, that individual file is likely incomplete.
Are you seeing a when you try to extract the file? CallOfDutyInfiniteWarfare.part13.rar
Open part1.rar in WinRAR , click "Tools," and then "Repair archive." This only works if the uploader included "Recovery Records." If WinRAR or 7-Zip reports a "Checksum error"
If you are getting an error about this specific "solid piece," it usually means part13 is corrupt or missing. Because solid archives treat all parts as one stream, damage to a single part often prevents the extraction of any files that follow it in the sequence. Because solid archives treat all parts as one
Many repackers, such as those discussed on r/CrackWatch , include a .sfv or .md5 file. Use a tool like QuickSFV to check if your part13 matches the original source. Troubleshooting Steps