Hello Yairi,
thanks for your answer. I got the update Image files from Mellanox.
Procedure was, install first "image-PPC_M460EX-SX_3.4.0012.img 2014-12-15"
after this update the WebUI was working.
2nd update was "image-PPC_M460EX-3.4.2008.img 2015-06-12"
3rd update "image-PPC_M460EX-3.5.1006.img 2016-03-09"
and 4th was "image-PPC_M460EX-3.6.1002.img 2016-06-09"
I installed all updates in CLI mode from a USB stick. But not all USB sticks are good for this.
Only an old USB 2.0 4GB stick Fat32 formatted was working.