[object event] shown when clicking "start sharing"

[Shutoparu]

This could be a naive question, but whenever I try to click start sharing, nothing happens except a red "[object event]" text is shown under the preview box.
For now I'm only following the steps shown in quick start but things just seems to not work for me. I'm also confused about the reason to run an OME container because even if I shut the container down, the webpage gives me the exact same response. It could have been me to connect the wrong ports (maybe), but I would love any advice or tips to make the demo work.
Thanks in advance for any help :)

Edit:
Seems like I've made some error in my Server.xml file, resolved after fixing it