In Toad 17.1 for Windows, when you run a procedure from a package that returns an open cursor and you configure the execute interface so that the contents of that cursor are displayed in a window (Fetch into memory - View in grid), an error occurs if you try to count the rows returned with "Record count" over the modal window which shows the cursor content. The window freezes and the rest of TOAD becomes unusable waiting for the window response. Additionally, the modal window remains in the foreground, above any other window of another application. You need to kill the process and restart TOAD.
I understand that the difficulty may be due to counting the rows of a cursor that has already been completly fetched to display the results, but perhaps it would be useful to add that count to the display window or prevent the count command from being executed.