That's the current MRPI version (the tarball is versioned after the last commit in the full MRPI directory tree, the script after its own).
That return code is funky as hell, though.
Try again after rebooting your device, just in case?
And before you do so, replace
extensions/MRInstaller/bin/mrinstaller.sh with
this one.
This *should* output some more details about the failure in MRPI's log (or not

).