weird character not found

[Wolfgang Engelmann]

In one of my documents I get:

The following character in one of the insets is not represented in the 
current encoding and have been omitted:
–
Unchecking 'Literal' in the respective inset dialog might help.
But since there is no indication of the respective inset I tried to find 
it by using Edit> find and replace (advanced) and used
–  xxx for exchanging it. But it does not help to get rid of it, even 
after reconfiguring.
The same with a ω

Not a serious problem, just a warning, since the pdf file is produced.
The characters are somewhere in a note containing copy/paste stuff.

I guess there is a linux line command which would find it.

Wolfgang