Tomcat, web.xml and "[xX][mM][lL]" is not allowed

Problem So, I had the following issue when trying to run my web application from Eclipse deploying to a local Tomcat. The processing instruction target matching "[xX][mM][lL]" is not allowed.The processing instruction target matching "[xX][mM][lL]" is not allowed. Solution It turned out that I had an empty line at the beginning of my web.xml!