: You cannot open Part 5 on its own. You must have all preceding and succeeding parts (e.g., .part1.rar through the final part) in the same folder.
The software will automatically "bridge" all parts together to recreate the original large file (likely an .iso or a game folder). anno_1800__empress_.part5.rar
is a city-building game, and EMPRESS is a well-known group or individual in the game piracy/cracking scene. The file you mentioned is the 5th part of a split RAR archive. : You cannot open Part 5 on its own