RV180 1.0.5.4 Adminpage aren't working with OSX 10.11.6 / Safari 9.1.2

The adminpages of RV1801.0.5.4 aren't working with OSX 10.11.6 / Safari 9.1.2., the menu items will not unfold and there's no information on the main part of the window.

Safari gives a lot of errors, the first 2:

Sandboxing 'https://router2.ovwv.lan/platform.cgi?page=blank.htm' because it is using HTTP/0.9.

[Error] Blocked script execution in 'https://router2.ovwv.lan/platform.cgi?page=leftMenu.htm&date=Sat%20Aug%2...(CEST)' because the document's frame is sandboxed and the 'allow-scripts' permission is not set. (x2)

Please fix the firmware of this device.