Upgraded 750G from 4.1 to 6.4 webfig not working

I Upgraded my router 750G from 4.1 to 6.4, but webfig is not working when i go to http://ip:port , if i use http://ip:port/webfig is working fine . The http://ip:port is showing the old webbox , how i can fix this ?

  routerboard: yes
  model: 750G
  current-firmware: 3.10
  upgrade-firmware: 3.10



 #   NAME                                                                             VERSION                                                                             SCHEDULED              
 0   ipv6                                                                             6.5                                                                                                        
 1   routing                                                                          6.5                                                                                                        
 2   routeros-mipsbe                                                                  6.5                                                                                                        
 3   wireless                                                                         6.5                                                                                                        
 4   ppp                                                                              6.5                                                                                                        
 5   hotspot                                                                          6.5                                                                                                        
 6   security                                                                         6.5                                                                                                        
 7   dhcp                                                                             6.5                                                                                                        
 8   mpls                                                                             6.5                                                                                                        
 9   system                                                                           6.5                                                                                                        
10   advanced-tools                                                                   6.5

Have you clear the web browser cache ??
And pressed logout from webbox (webgui) ??

Yes i already did that and checked on another computer as well to be sure that its not caching.

just in case, make export of your current configuration and reinstall it using netinstall tool as it seems you have banding package installed.