We chased a fun bug in the afternoon after we deployed our new package to our staging server. Symptom: Our customized Content Query Web Parts stops rendering. But we noticed they were still functioning when we drop into edit mode. Hint: This gave us the hint that our XSL was probably stuffed – but it checked out ok in SharePoint designer * . Detective Work: Digging through the SharePoint logs, we came across two lines that are incredibly suspicious: 0x17C4 Windows SharePoint Services Web Parts 89a1...