XML-22029: (Error) Cannot transform child 'otherwise' in 'choose'

Question

I am getting below error : XML-22029: (Error) Cannot transform child 'otherwise' in 'choose'.

We are migrating 11g bpel composite to 12c.

The xsl version is 1.0

Sample xsl :

<when>

  <element/>

</when>

<otherwise>

    <when>

      <element/>

    </when>

</otherwise>

<otherwise> getting error here

  <when>

    <element/>

  </when>

 </otherwise>