Upgrade from 4.2.11 to 4.2.13 (or 4.2.14):
Macro gives error message on page: "Error rendering macro 'auibutton' : null"
System info:
Confluence 5.8.9
Operating System Linux 3.10.0-327.3.1.el7.x86_64
Application server Apache Tomcat/8.0.23
Java version 1.8.0_66