Problem

User macros, such as the Indent Macro, don't work in Confluence version 3.1. 

Cause

Those macros use the getGlobalHelper() method, which was deprecated and removed in 3.1. See Confluence 3.1 Deprecated Code Cleanup.

Resolution

Replace:

#set($globalHelper=$action.getGlobalHelper())

with

#set($globalHelper=$action.getHelper())