Since Confluence 7.0.1, there is a change in <Confluence_Installation>/confluence/WEB-INF/classes/velocity.properties that includes a Secure Introspector to disable certain classes' accessibility.
This affected some of the User Macros created by the customers that is making use of the restricted class.
Here are some examples of the user macro being affected by this change, mostly related to getting user's information:
There is no alternative way to obtain user information after the change has been implemented. As this change is based on a security measure, it is not recommended to make any custom changes to the velocity.properties.
Suggesting to have an alternative way to obtain the user information so that the customers can continue to have custom User Macro that is able to pull user's information