The project runs fine when I deploy it to Tomcat. The problem is the editor: it flags the taglib URL, and the "if" tag, like it's never heard of them. This is a project that I've been working on for a long time; I'm pretty sure it's not a problem with the project, but with the IDE settings. I must have changed something, but I have no idea what. If it was just changing the color, I could live with that, but now I can't use code completion for tag names or attributes.