What *exactly* are you doing? Are you trying to insert the VIs on stereo instrument tracks?
Did you run all installers? And they finished OK?
Are the .aaxplugin files for those plugins in the plugin folder (C:\Program Files\Common Files\Avid\Audio\Plug-Ins). Don't guess, check with the Windows desktop UI that they are there and tell us what you find.
If so, try trashing prefs (if you have never done that read about it under troubleshooting steps under "Help Us Help You" up the top of each DUC web page, but in practice use this tool:
https://www.pro-tools-pc.us/category-s/1514.htm)
Do you see the plugin load in the splash screen when Pro Tools starts up?