Java. Lang. linkageerror: loader constraints violated when linking javax/El/expressionfactory class

Severe: servlet. Service () for servlet JSP threw exception
Java. Lang. linkageerror: loader constraints violated when linking javax/El/expressionfactory class
At org. Apache. jsp. login_jsp. _ jspinit (login_jsp.java: 23)
At org. Apache. Jasper. runtime. httpjspbase. INIT (httpjspbase. Java: 52)
At org. Apache. Jasper. servlet. jspservletwrapper. getservlet (jspservletwrapper. Java: 159)
At org. Apache. Jasper. servlet. jspservletwrapper. Service (jspservletwrapper. Java: 329)
At org. Apache. Jasper. servlet. jspservlet. servicejspfile (jspservlet. Java: 320)
At org. Apache. Jasper. servlet. jspservlet. Service (jspservlet. Java: 266)
At javax. servlet. http. httpservlet. Service (httpservlet. Java: 803)
At org. Apache. Catalina. Core. applicationfilterchain. internaldofilter (applicationfilterchain. Java: 290)
At org. Apache. Catalina. Core. applicationfilterchain. dofilter (applicationfilterchain. Java: 206)
At org. Apache. Catalina. Core. standardwrappervalve. Invoke (standardwrappervalve. Java: 233)
At org. Apache. Catalina. Core. standardcontextvalve. Invoke (standardcontextvalve. Java: 175)
At org. Apache. Catalina. Core. standardhostvalve. Invoke (standardhostvalve. Java: 128)
At org. Apache. Catalina. Valves. errorreportvalve. Invoke (errorreportvalve. Java: 102)
At org. Apache. Catalina. Core. standardenginevalve. Invoke (standardenginevalve. Java: 109)
At org. Apache. Catalina. connector. coyoteadapter. Service (coyoteadapter. Java: 263)
At org. Apache. Coyote. http11.http11processor. Process (http11processor. Java: 844)
At org. Apache. Coyote. http11.http11protocol $ http11connectionhandler. Process (http11protocol. Java: 584)
At org.apache.tomcat.util.net. jioendpoint $ worker. Run (jioendpoint. Java: 447)
At java. Lang. thread. Run (thread. Java: 595)

Explanation:
Loading violates constraints.

Cause of error:
The el-api.jar under tomcat/lib conflicts with the WEB-INF under the project el-api.jar/lib directory.

Solution:
Delete the el-api.jar under the project directory.