I created a forum and it all works well when I open the forum url in another browser and it displays how I want, except when I press on a topic or even the login or member subheading pages it directs to a page i've never seen before which I attached below.

Have a look at my forum page: firsttouch.com.au/community/ as well to see what I mean, not sure what's wrong or what's doing this and I've already tried deactivating all plugins to see if any are the issue and it's not that.

Any help is extremely appreciated!