: Multi-part RAR files are extremely sensitive. If Part 4 is from a different version or a different uploader than Part 1, the extraction will fail with a "checksum error."
: Check the Steam Community Hub for patch notes regarding v2.0.8.7 if you are looking for specific technical changes made in that version. Night of the Dead v2.0.8.7.part04.rar
If you are looking for the game to play it safely and support the developers (jacktostudios), you can find it here: : Night of the Dead on Steam : Multi-part RAR files are extremely sensitive