Emergency department (ED) electronic tracking boards provide a snapshot view of patient status and a quick link to other clinical applications, such as a web-based image viewer client to view current and previous radiology images from the picture archiving and communication systems (PACS). We describe a case where an update to Microsoft Internet Explorer severed the link between the ED tracking board and web-based image viewer. The loss of this link resulted in decreased web-based image viewer access rates for ED patients during the 10 days of the incident (2.8 views/study) compared with image review rates for a similar 10-day period preceding this event (3.8 views/study, p<0.001). Single-click user interfaces that transfer user and patient contexts are efficient mechanisms to link disparate clinical systems. Maintaining hazard analyses and rigorously testing all software updates to clinical workstations, including seemingly minor web-browser updates, are important to minimize the risk of unintended consequences.