[Fr.dr.k S.d.rst.dt]

Have you double checked if you have downloaded the correct version from racedepartment?
SRS use 2.61 and latest is 2.7, so if you only press the download button and install that version you will have the wrong version.
https://www.racedepartment.com/downloads...27/history

If you have the correct version and still get checksum fail, try to delete the launcherdata folder in my documents/assetto corsa