https://bugs.winehq.org/show_bug.cgi?id=51507
--- Comment #3 from Dominique Martinet dvufhr.nznqarjf@noclue.notk.org --- had similar traces (wsock32 -> iphlpapi -> nsi.dll not found error chain) In my case ~/.wine/drive_c/windows/system32 contained the 64bit version of the libs (/usr/lib64/wine/x86_64-window/wsock32.dll etc), but looking at strace the application did not check there at all.
I've copied the 32bit version of the libs to ~/.wine/drive_c/windows and program started working again.
I guess it might be because I'm running 32bits programs in a 64bit prefix, but that always worked this way so not sure what it's complaining about now about all this time... Well, just copying a few files worked, not going to bother until it happens again.