If you answer “yes” to the following questions, then please read on: Do you have a Synergy UI Toolkit application? Do you use standard (not ActiveX) list processing with a load method? Do you run your software on Microsoft Windows 10?

Windows 10 offers a new feature that allows you to mouse over a list and use the mouse wheel to scroll the list, without the list actually getting focus. It’s a great feature, but if you have a standard list displayed in your UI Toolkit application which uses a load method – then that mouse-over scroll operation will attempt to “process” the list and cause the list load method to execute. Does not sound too bad – but if you have method data being passed through from the l_select() or l_input() routines then this data will not be passed to your load method, because you are not actually in l_select() or l_input(). Also, because the list has not gained focus you have potentially not been through your “my list is gaining focus so set up the load parameters” logic, which again means when your load method executes it’s in an unknown state.

When your load method executes in this “unknown” state and you try to access method data or your uninitialized load data then a segmentation fault may occur. The user uses the Wheel, the list attempts to Scroll and Oops your application crashes.

Thankfully, the Synergex team have found the issue and resolved it – and the fix will be in the upcoming 10.3.3b patch. If you are experiencing this issue today and need a resolution now, you can contact support who can provide you with a hotfix.