This is an annoying problem I have had a few times: I open a SQL Server Integration Services (SSIS) project in SSDT, and see that the Toolbox pane is empty, displaying a “There are no usable controls in this group. Drag an item onto this text to add it to the toolbox.”. What the? What happened to all my SSIS tasks? Turns out, SSDT has two toolboxes: one called “Toolbox” and a new one called “SSIS Toolbox“. So, I had the “Toolbox” window open when I really just needed the “SSIS Toolbox” open. So I go to the “View” menu item, but “SSIS Toolbox” is not listed! Instead, there are two new buttons on the far-right of the screenshot below, with the second the button to click to open the ”SSIS Toolbox”:
Very confusing! Hopefully this will help you avoid the confusion and wasted time I had encountered looking for my SSIS tasks.
UPDATE: You will see a “SSIS Toolbox” under View -> Other Windows if the a dtsx window has the focus (along with menu items “Variables”, “Log Events”, and “Getting Started”), but not if any other window has the focus. Very confusing as that menu item should always appear no matter what window has the focus.