Hello,
the title of your Window tells me that you are running a duplicate version of laszip that was copied onto the desktop. This version being outside the LAStools\bin folder where it expects to be located is not able to find the 'psc.csv' file ...
If instead you run laszip.exe from its LAStools\bin\laszip.exe location, you will not get this warning.
That said ... laszip.exe does not really need access to this file (unless you add a CRS on the fly) to operate correctly, so you may just disregard the warning.
Martin