That behavious looks like a hash/crc check.
It's possible that there is a file in the game that contains a list of hashes/checksums/crc for each available file and it's compared with the calculated one of the file on disk, if it doesn't match the game will not load the file.
A second reason may be related to the version of Rar that the game is using.
The files in that archive are dated 2001 so it's possible that using a recent version of Rar/winrar creates an archive which is not supported by the game.
Try using a rar 3.x that is able to create a RAR4 archive like the one you provided and let us know if it works.
Edit: old versions are available on the official homepage like https://www.rarlab.com/rar/wrar300.exe
Edit2: probably you can create a rar4 version with the -ma4 option of the current rar.exe