PlateSolve 2 is super fast and reliable but very picky about the setup.
Have you tried completely uninstalling before doing the reinstall? Leftover settings files may be causing issues.
SGP comes with Plate Solve 2 built in. If you did a separate installation of PlateSolve 2 from the Planewave web site, it may be causing trouble. Be sure you are using the built-in version.
Download both the APM catalog installer and the UCAC3 catalog from Planewave:
If I recall correctly, APM installs via an app installer but the UCAC3 catalog just needs to be unzipped. I put it in the same directory as the APM catalog.
- In the control panel > plate solve tab > plate solve interface, select PlateSolve 2. Click settings.
When PlateSolve 2 opens, choose file > configure catalog directories...
In the resulting dialog, make sure the APM and UCAC3 directories point to where you installed/saved them. Status should say OK in green for each.
PlateSolve 2 relies on hints to process an image. In control panel > camera, set your image scale to the appropriate value for your optical train. Since you have astrometry.net working, you can get the value there.
Finally, PlateSolve 2 will only work when it has a pretty good idea of where your scope is pointing in the sky. When you first power up your rig and polar align, you will need to do a blind solve and sync. (It's grayed out below because my mount is powered off.)
With the blind sync done, the next time you slew to an object, the scope's position and the image scale you set previously will give PlateSolve 2 the hints it requires to do a plate solve in just a few seconds.
Hope this helps. Good luck.