Ok, this is more information than you want since you have it fixed...
But here's what I was trying to say earlier today...
If you go to Utilities > Cakewalk Plugin Manager
You can go into VST Instruments and find Dimension Pro...
Next click plugin properties and uncheck Configure as Synth (this will mess you up like you were before).
Once done, Dimension Pro moves to the VST Audio Effects and out of the VST Instruments (VSTi) category.
This was your case.
Now, to switch it back, you can go to VST Audio Effects, click on Dimension Pro and select Plugin Properties and check Configure as Synth > OK.
Now it moves out of the VST folder and back to the VSTi folder.
Why might you want this?? Good question!! Once you configure a VST as a VSTi you can send Midi to it. And you say, 'But I can just open the VST effect window and click on the VST3 drop down and choose 'Enable Midi Input'! True enough today, young Jedi... but in days long past before your father's father, this was not the way. To route Midi into a regular VST effect you needed to configure the effect as a VSTi. And so was born the option.
There were issues with the VST as a VSTi. One issue was tempo sync. As a VST, TH3 tempo sync works fine. Configured as a VSTi, Tempo Sync was disabled for the effect. At least that is my memory of the dark days before VST3. And so young warriors would switch their guitar amp sims between VST and VSTi depending on whether they were sending midi to the amp sim to manipulate effects or not.
Knowing all this, it may not have been necessary to reset/rescan. You could have just popped open this window and checked the box.