Very odd! I accessed the forum from my work computer and I can see it. Although I noticed when I tried on mobile the "Nav Tree" disappears behind the header. Maybe its a browser based issue?
Error - Cannot read property 'toLowerCase' of undefined
Hello! Please help me fix this error, when I try create new user in ACP or try accept user registration, i have this "Cannot read property 'toLowerCase' of undefined".
Are there any errors in your nodebb logs?
A good starting point would be to disable all third-party plugins and see if that resolves the issue.