Error when clicking the scrollbar of an Event Sheet

Error:

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An invalid argument was encountered.
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When an event sheet opens for the first time by double-clicking the sheet in the project list, clicking on the scroll-bar will cause the error to pop up. It pops up not once, but three times in a row (you have to hit OK three times).

If you click inside the event sheet window (not on the scroll-bar) then the error will not occur. You are able to safely use the scrollbar after that.

The event sheet must have at least one event in it for the scrollbar to appear.

How to recreate:

1. Download the attached file (clicky.cap) and open it.

2. Navigate to the Project tab.

3. Double-click the event sheet labeled "clicky." It will open in a new window.

4. Immediately click on the scrollbar, and the error will occur. After clearing the error message popups, the error will continue to occur until you click inside the body of the event sheet window.