The term "latest" is relative. Nokia stopped supporting Symbian S60v3 in 2012. However, the "latest" flash file refers to the final firmware version released for the RM-346 before support ended. For the E71, the final stable versions are generally around (depending on the product code).
Flashing firmware can permanently "brick" your device if done incorrectly or interrupted. Data Loss: nokia e71 rm346 latest flash file