shell script that used to work now fails

Hi,
I have been running this script which I took from a photographer's website for many years and it always worked. Now there is aproblem, which I cannot locate.
Can anyone help? Here is the script:
exiftool -P -d '%Y-%m-%d at %H-%M-%S' \
'-filename<${FileModifyDate;}%-c.%e' \
'-filename<${GPSDateTime;}%-c.%e' \
'-filename<${MediaCreateDate;}%-c.%e' \
'-filename<${ModifyDate;}%-c.%e' \
'-filename<${DateTimeOriginal;}%-c.%e' \
"$1"
And here is the log: Shellscript exited with non-successful status code: 127
I have been running this script which I took from a photographer's website for many years and it always worked. Now there is aproblem, which I cannot locate.
Can anyone help? Here is the script:
exiftool -P -d '%Y-%m-%d at %H-%M-%S' \
'-filename<${FileModifyDate;}%-c.%e' \
'-filename<${GPSDateTime;}%-c.%e' \
'-filename<${MediaCreateDate;}%-c.%e' \
'-filename<${ModifyDate;}%-c.%e' \
'-filename<${DateTimeOriginal;}%-c.%e' \
"$1"
And here is the log: Shellscript exited with non-successful status code: 127