/tmp directory is not executable. It is mounted with the nosuid and noexec flag. Run mount | grep tmp command to check for the options.
1 - Edit the /etc/fstab file and removed the nosuid and noexec from the /tmp mount
Please note this file may differ on other operating systems. Please check operating system documentation for the mounting on booting file.
2 - The unmount
3 - Then remount
4 - Verify the flags are not still visible on the /tmp directory using mount -a | grep tmp command