Good evening. To solve this problem, simply install server version 4.4.0 on your host machine. By itself it should have already automatically installed version 4.4.0 for the web interface. I tested it now and it worked.
If you use the windows client you have to do the same of course
https://netxms.org/download/releases/4.4/netxms-server-4.4.0-x64.exe
https://netxms.org/download/releases/4.4/netxms-webui-4.4.0-x64.exe
https://netxms.org/download/releases/4.4/netxms-client-4.4.0-x64.exe