Apparently it would only give an error if you tried to run a localhost server within the client editor (when pressing the upper-right corner HTML5 symbol). All I did was go to my client's export location, type cmd in the path bar, type python -m http.server 8000 in cmd, go to chrome and open localhost:8000, then run my own server and finally open the file from the browser and it worked. Didn't test too much before asking... my bad!