You cannot use part01.rar alone. You must download all parts ( part01 , part02 , ..., partN.rar ) provided by the source.
Part 1 of a multi-part .rar archive (split compressed file). DODI_DKR_DSRT_RLY.part01.rar
This file is necessary to install a compressed, smaller-sized version of the game. 📋 Requirements to Install You cannot use part01
You need WinRAR or 7-Zip to extract the contents. DODI_DKR_DSRT_RLY.part01.rar