DLL load failed while importing objectify: The specified module could not be found.

[fera0013]

I keep getting

DLL load failed while importing objectify: The specified module could not be found. File "D:\simple-client-server-xml\server.py", line 13, in <module> from opcua import ua, uamethod, Server ImportError: DLL load failed while importing objectify: The specified module could not be found.

When I try to run server examples. Based on a search in the github repository, the line

from lxml import objectify

in opcua/common/structures.py could be the culprit, but when I pip install lxml I get the feedback, that the requirement is already satisfied.

What could be the problem here?