Try this,
In c:\Users\USERNAME.tizen (note it is a hidden file) there is sdbkey and sdbkey.pub. hide, rename or move them to another folder.
Restart your computer to clear any cache and relaunch GWS
do all the normal things again on your watch be sure debugging is on tap 5 times on software to enable developer options if they aren’t on.
reboot your watch by holding down on the home key until it says rebooting.
set your watch face as a pre-installed watch face
and try to connect from GWD and watch your watch face
keep your watch active and watch for the RSA acceptance
if it shows allow it
If you still get the error message then it is probably a bad certificate and we can deal with that.
Ron
Samsung Developer Program