Trouble installing Multimedia Server

[ideasmonkey]

Hi there.
Complete newbie here. I've tried following guides on youtube and through the TerraMaster website, but I keep getting stuck at the same point.
I open the App and am presented with the 'General' Tab. I click on the box that Enables Multimedia Server and immediately get a popup window that says 'Tips - The changes have not been saved, are you sure you want to leave?'. I can click 'Save', 'Cancel', or 'Confirm', but nothing happens. The popup window just appears again, giving me the same options.
I've tried clicking on other boxes and got the same response.
The only way to get out of the pop-up is to close the app.
I've tried re-installing it, but the same thing happens every time.
I'm clearly doing something wrong, or haven't set something up right to begin with.
Does anybody have any ideas what I'm doing wrong?

Pics below for reference:
download/file.php?mode=view&id=2971
download/file.php?mode=view&id=2972

[TMzethar]

Please tell us the TNAS model and TOS version you are using.
Please try clearing the browser cache or restarting TNAS. And tell us if it works.