Here's a good one... I had a VST FX plugin called "son of a Pitch" I was trying to use in one of my songs.  It wasn;t working properly so I uninstalled if from my PC, but it's still showing in the plug in manager.  When I try to exclude it from the plug in manager I get an error message that it can;t find the file path for the plug in, which makes sense as the plug in was uninstalled.  But I want to remove it from my plug in manager as I'm trying to diagnose some crashing problems I'm guessing may be from one of my plug-ins.  I've checked every track and bus FX bin and it is not listed anywhere as being in use.  Appreciate some ideas. 

When you say plug-in manager I assume you mean Cakewalk plug-in manager where all you plug-ins are listed and not one you created. If so then go to this registry entry and remove just that plug-in from the list if it's there and it should no longer show in the manager.
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR\Cakewalk VST X64\Inventory

Hi. Have you done a vst reset and scan after uninstalling your plugin? Preferences (P), File, Vst Settings. Check scan failed and existing plugins before scanning.
All the best.

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