No DashboardUI but still access with SSH

Hi guys. 

As my subject sais, I have no dashboard. But, the good thing is, I can still access my NAS threw my SSH.

Plus, I think my apache2 is messed up.

*Update*

When I try to access the _/usr/sbin/apache2 _this error shows up: Directory /usr/lib/apache2/mpm-prefork/apache2: no such file or directory

What should I do?

Best regards, Cophe

Install a new firmware version via ssh. That will get you the UI back.