eclipse checkstyle error cannot initialize module TreeWalker - TreeWalker is not allowed as a parent of RegexpHeader

Question

I am using checkstyle version 5.6.1 .I get this error when I try to use a user defined check style template :

cannot initialize module TreeWalker - TreeWalker is not allowed as a parent of RegexpHeader

Answer 1

Probably your configuration is similar to the following one:

<module name="Checker">
  <module name="TreeWalker">
    <module name="RegexpHeader">
      ...
    </module>
  </module>
</module>

You need to change it to:

<module name="Checker">
  <module name="RegexpHeader">
    ...
  </module>
  <module name="TreeWalker">
    ...
  </module>
</module>

because TreeWalker is not allowed as a parent of RegexpHeader.