I recently pulled a repository (using the GIT clone command) from our codebasehq account and landed up with this error while starting the server using the command script/server.

script/server: Permission denied

After a quick search I figured a fix and the possible cause of the problem. 

Fix: 

On your bash (terminal) run: chmod 755 script/server

Possible Cause: 

The source pushed to the git server was from a Windows machine.