I am using Change Stage smart shape to switch to different stage, but then my previous step is not getting marked completed. I have the "Close open assignments from current stage on change" option selected.
I do not believe there is a hot fix for this. As a rule we recommend upgrading to the lastest version to obtain the latest functionality. If this is not possible please submit a Service Request (SR) so that one of our Customer Support technicians can work with you on this. You can do so by contacting Pegasystems Global Technical Support through My Support Portal.