SQL Worksheet is not displaying in SQL Developer
<p>Suddenly SQL worksheet is not displaying in my SQL Developer. When I click on '<strong>Open SQL Worksheet</strong>' or <kbd>Alt+F10</kbd> nothing will appear.</p>

<p>I have tried many things such as: uninstalling SQL developer; cleaned the appData; changing java version; change SQL Developer version; and so on. But nothing has worked. Help?</p>