When I was debugging my project yesterday, I stumbled upon this error message: "Unknown tag (c:forEach)." 😓 It was frustrating because everything seemed fine until that point. The issue stemmed from a missing library in my JSP file. In Java web development, `` is part of the JSTL (JavaServer Pages Standard Tag Library) tags. Without including the correct dependencies or taglib directives, the server can't recognize it.

After hours of searching and referencing documentation, I finally added the JSTL core library to my project. To fix it, I included this line at the top of my JSP file: `<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>`. ✅ Once done, the error disappeared like magic!

Remember, even small mistakes like forgetting to import libraries can cause big headaches. Always double-check your imports before panicking. 😊 If you're ever stuck, Stack Overflow is your best friend! 🌟