Hi Armin,
Please come to the latest patch on 04.3.05 (CP08) before upgrading to 4.4 as direct upgrade from 04.3.05 to 04.4 is not supported
(04.3.05 should be on minimum CP06 patch to upgrade to 04.4 as per my knowledge).
You can download the CP08 patch from
https://support.broadcom.com/web/ecx/solutiondetails?aparNo=99111714&os=WINDOWS-ALL
Thanks,
Ram Sharma