I had the same issue and in my case it was OpenRefine that was blocking the port, hence why it worked successfully on the first attempt only. The solution was to kill the offending process.
I would advise others to try this first as my limited understanding of OR leads me to believe that changing the .ini file in the manner described could leave a machine vulnerable to malicious incoming connections.
For linux:
1) open a terminal and use 'top' to locate the 'java' process (hint: use shift-M to sort by memory)
2) hit 'k' to kill the process, provide the PID and hit enter.
3) use option '9' to ensure the process is killed.
4) cd back to the OR folder and run './refine' in the usual way.