JVMVRFY012: VerifyError for JSTL Tags - Foreach & Set tags - spring-mvc

Question

IBM WAS: 8.5.5 Version
On JSP pages have & tags, I receive below error
Error 500: java.lang.Exception: java.lang.VerifyError: JVMVRFY012
stack shape inconsistent; class=com/ibm/_jsp/_desktop,
method=_jspx_meth_c_set_0(Ljavax/servlet/jsp/PageContext;)Z, pc=73;
Type Mismatch, argument 1 in signature
org/apache/jasper/el/ELContextWrapper.:(Ljavax/el/ELContext;Ljavax/el/FunctionMapper;)V
does not match Exception Details:
Location:
com/ibm/_jsp/_desktop._jspx_meth_c_set_0(Ljavax/servlet/jsp/PageContext;)Z
#73: JBinvokespecial Reason: Type
'org/apache/jasper/runtime/ProtectedFunctionMapper' (current frame,
stack[8]) is not assignable to 'javax/el/FunctionMapper'
Current Frame: bci: #73 flags: { } locals: { 'com/ibm/_jsp/_desktop',
'javax/servlet/jsp/PageContext', 'javax/servlet/jsp/JspWriter',
'org/apache/taglibs/standard/tag/rt/core/SetTag' } stack: {
'org/apache/taglibs/standard/tag/rt/core/SetTag', 'uninitialized',
'uninitialized', 'java/lang/String', 'javax/el/ExpressionFactory',
'uninitialized', 'uninitialized', 'javax/el/ELContext',
'org/apache/jasper/runtime/ProtectedFunctionMapper' } Stackmap Table:
append_frame(#128,Object[#127],Object[#231],integer)
On reading https://www.ibm.com/support/pages/ibm-java-linux-howto-resolving-javalangverifyerror-jvmvrfy012-stack-shape-inconsistent, understand that the reason could be
code is compiled against a different library than the one being used at runtime
a class tries to extend a class declared as final
a method tries to override a super method that is declared as final
a wrong argument is passed to a method
It does look to be #4 - but the same code works in Tomcat and does not work in IBM WAS and am unsure why WAS is passing an incorrect argument. Any suggestions on how we can resolve this issue?

Answer 1

You may want to explore Servlet/JSP version compatibility.
WAS: 8.5.5 reference
Servlet 3.0
JSP 2.2
If you happen to be using Spring Boot:
2.2.x and 2.1.x require Servlet 3.1+
2.0.x supports Servlet 3.0

Answer 2

This looks like a cross-linkage between the javax.el library in your application and the version packaged in the server. When using PARENT_LAST, any Java EE APIs you include in the application are loaded twice, once from the server and once from the application (because the application loader doesn't delegate that load to its parents). Depending on the other classes/packages in play, you can have an instance in which a class ends up directly referencing one instance of the class and indirectly (through some other reference) referencing the other instance, and the JVM will throw a VerifyError in that scenario.
The easiest answer: If you are not 200% sure you NEED the version of the javax.el classes in the app, remove them, and this specific error should be impossible. If you are definitely dependent on that version, then it becomes trickier, as it might require adding additional stuff to the application (to avoid picking stuff up from the server), or it may be that this specific library simply can't be safely overridden with PARENT_LAST loading. That analysis would require a deeper look at the error stack and possibly a dive into detail trace of the class loading.