First there's the obligatory "cygwin has nothing to do with Linux
so you really should be asking elsewhere" refrain.
Then there's an observation: etheral is long dead and replaced
by wireshark. Why would you want to mess with something so old?
And also- since you are using Windows, why not just use
the Windows version of Wireshark and get on with whatever
scan you were contemplating?
As to your direct question- sorry no idea though as you
no likely expect it appears to be shared library problem.
Maybe newer code wil be supported better?
Stan