create-space-button macro throws NPE when using preview

java.lang.NullPointerException
at com.atlassian.confluence.renderer.radeox.macros.CreateSpaceButtonMacro.getHtml(CreateSpaceButtonMacro.java:52)
at com.atlassian.confluence.renderer.radeox.macros.AbstractHtmlGeneratingMacro.execute(AbstractHtmlGeneratingMacro.java:44)
at com.atlassian.renderer.macro.RadeoxCompatibilityMacro.execute(RadeoxCompatibilityMacro.java:149)
at com.atlassian.confluence.renderer.v2.macros.RadeoxCompatibilityMacro.execute(RadeoxCompatibilityMacro.java:26)
at com.atlassian.renderer.v2.macro.ResourceAwareMacroDecorator.execute(ResourceAwareMacroDecorator.java:45)
at com.atlassian.renderer.v2.components.MacroRendererComponent.processMacro(MacroRendererComponent.java:340)
at com.atlassian.renderer.v2.components.MacroRendererComponent.makeMacro(MacroRendererComponent.java:241)
at com.atlassian.renderer.v2.components.MacroRendererComponent.makeMacro(MacroRendererComponent.java:130)
at com.atlassian.renderer.v2.components.MacroRendererComponent.handlePotentialMacro(MacroRendererComponent.java:115)
at com.atlassian.renderer.v2.components.MacroRendererComponent.render(MacroRendererComponent.java:77)
at com.atlassian.renderer.v2.V2Renderer.render(V2Renderer.java:54)
at com.atlassian.renderer.v2.V2SubRenderer.render(V2SubRenderer.java:44)

One of these is null when it should not be:

I18NBean i18NBean = GeneralUtil.getI18n();
HttpServletRequest request = ServletActionContext.getRequest();