Following the just released update the location of SickChill.py has changed again so I had to edit the SickChill Service Argument line in NSSM from
"C:\SickChill\Python3\tools\Scripts\SickChill.py" --nolaunch --port=8081 --datadir="C:\SickChill\Data"
to
"C:\SickChill\Python3\tools\Lib\site-packages\SickChill.py" --nolaunch --port=8081 --datadir="C:\SickChill\Data"
Following the just released update the location of SickChill.py has changed again so I had to edit the SickChill Service Argument line in NSSM from "C:\SickChill\Python3\tools\Scripts\SickChill.py" --nolaunch --port=8081 --datadir="C:\SickChill\Data" to "C:\SickChill\Python3\tools\Lib\site-packages\SickChill.py" --nolaunch --port=8081 --datadir="C:\SickChill\Data"