Is Seer working in Explorer? If not, there is something wrong with Seer installation.
Otherwise:
If the Seer option can be selected in Settings>Preview, then OC sees that it is installed.
Make sure Seer and OC are not running elevated (not running as Administrator)
You can try getting new version by going to Settings>Advanced>Reinstall
It will download 3.53
Try to open preview of any image, then right-click OC in system tray > Open Log
and see if there is any error shown (must be 3.53 as previous versions do not log Seer interaction errors)
Seer may also log an error. Open path in OC:
%TEMP%/Seer
And see if there is any errors in seer.log file