Version 3.1.0

I installed version 3.1.0 but im having issues with the side menu and the links, they look like below with an error at the bottom when i click on any of them.

/tac.cgi" target="">Tactical Overview
/statusmap.cgi?host=all" target="">Map
/status.cgi?hostgroup=all&style=hostdetail" target="">Hosts
/status.cgi?host=all" target="">Services
/status.cgi?hostgroup=all&style=overview" target="">Host Groups
/status.cgi?hostgroup=all&style=summary" target="">Summary
/status.cgi?hostgroup=all&style=grid" target="">Grid
/status.cgi?servicegroup=all&style=overview" target="">Service Groups
/status.cgi?servicegroup=all&style=summary" target="">Summary
/status.cgi?servicegroup=all&style=grid" target="">Grid
/status.cgi?host=all&servicestatustypes=28" target="">Problems
/status.cgi?host=all&servicestatustypes=28" target="">Services (/status.cgi?host=all&type=detail&hoststatustypes=3&serviceprops=42&servicestatustypes=28" target="">Unhandled)
/status.cgi?hostgroup=all&style=hostdetail&hoststatustypes=12" target="">Hosts (/status.cgi?hostgroup=all&style=hostdetail&hoststatustypes=12&hostprops=42" target="">Unhandled)
/outages.cgi" target="">Network Outages

Error when clicking any of the links:

Not Found
The requested URL /nagios/< was not found on this server.

try install php package