When trying to load Greenhouse c4a1555 in an STS server:
- STS (2.8.1)
- (via Run-As, run on server)
- VMware vFabric tx Server v2.5 + jre: jdk1.6.0_25 + tomcat-7.0.20.B.RELEASE

I get the following error:

org.springframework.web.util.NestedServletExceptio n: Handler processing failed; nested exception is java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader) previously initiated loading for a different type with name "javax/el/ExpressionFactory"
org.springframework.web.servlet.DispatcherServlet. doDispatch(DispatcherServlet.java:949)
org.springframework.web.servlet.DispatcherServlet. doService(DispatcherServlet.java:827)
org.springframework.web.servlet.FrameworkServlet.p rocessRequest(FrameworkServlet.java:882)

Adding the following to pom solved the exception problem (info may help someone):

Code:
		<dependency>
			<groupId>javax.el</groupId>
			<artifactId>el-api</artifactId>
			<version>2.2</version>
			<scope>provided</scope>			
		</dependency>