Accidentally, I have clicked on “Add/Remove Servoy Solution Nature” option of the Activated Solution and instantly, that solution has deleted from the list of All Solutions . But, the solution is present in the WorkSpace. How can I able to retrieve my Solution?
Go to Window - Show View and type navigator, to add the navigator view to your perspective. In that view, you can see your solution again. right-click it and add the Servoy Nature again.