Problems with Permission denied

Hello,
I’m new to Docker and trying to install some prepacked software (on CentOS 7). Docker seems to start OK but when I call the script to install the software, I’m getting the error message:
/bin/sh: 1: /entry.sh: Permission denied
Changing the permissions to the script file does not make any difference. I don’t fully understand which permission is complaining about or which file is “entry.sh.”
Thanks.