This fixed it for me with one slight change/clarification which I inserted as "3a". The words between the *s are my own observations. (I copied the rest from the old Sonar Cakewalk support pages):
Cakewalk won’t launch
If your program will no longer launch, you may be able to resolve the problem by forcing it to re-write some settings behind the scenes. To do so, follow these steps:
1. Hold down the Windows key on your computer keyboard, then press the R key to open the Run prompt.
2. Type in the following: %appdata%\cakewalk
3. Click OK. This opens the Cakewalk content folder in Windows Explorer
*3a. Go UP one folder hierarchy level to view the folder you were just in*
4. Right-click the Cakewalk folder (*the one you were just in*) and select Rename on the pop-up menu.
5. Change the folder's name by adding the word “backup” to the end of it. For example: “Cakewalk backup”.
6. Close Windows Explorer and restart Cakewalk.
7. When prompted with the message “Cakewalk will now personalize your user settings”, click OK. (*For me at this point it just reopened without this notification but it did show that it was scanning my VST plugins which took a little bit of time and then I was good to go.*)
I hope this helps.
