This has happened on multiple pages within your site. Error as per below:

Cause:
Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null

Stack Trace: [hide]

Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
Referer URL: http://confluence.atlassian.com/pages/pageinfo.action?pageId=45164

Build Information:
Uptime: 2 days, 18 hours, 5 minutes, 48 seconds
Version: 1.4-DR4
Build Number: 115

Server Information:
Application Server: Orion/2.0.2
Servlet Version: 2.2
Database Dialect: N/A

Memory Information:
Total Memory: 494 MB
Free Memory: 126 MB
Used Memory: 368 MB

System Information:
System Date: Wednesday, 09 Feb 2005
System Time: 19:00:05
System Favourite Colour: Lime
Java Version: 1.4.2_04
Java Vendor: Sun Microsystems Inc.
JVM Version: 1.0
JVM Vendor: Sun Microsystems Inc.
JVM Implementation Version: 1.4.2_04-b05
Java Runtime: Java(TM) 2 Runtime Environment, Standard Edition
Java VM: Java HotSpot(TM) Server VM
User Name: j2ee
User Timezone: America/Chicago
Operating System: Linux 2.4.21-27.0.2.ELsmp
OS Architecture: i386

Request
Information:
URL: http://atlassian01.contegix.com:10082/500page.jsp

• Scheme: http
• Server: atlassian01.contegix.com
• Port: 10082
• URI: /500page.jsp
• - Context Path:
• - Servlet Path: /500page.jsp
• - Path Info: null
• - Query String: pageId=45164

Attributes:

• javax.servlet.error.exception : org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
• javax.servlet.error.message : Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
• os_securityfilter_already_filtered : true
• com.atlassian.johnson.filters.JohnsonFilter_already_filtered : true
• javax.servlet.error.request_uri : /pages/viewattachments.action
• javax.servlet.error.status_code : 500
• os_authstatus : null
• _sitemesh_filterapplied : true
• javax.servlet.error.servlet_name : action
• webwork.valueStack : com.opensymphony.xwork.util.OgnlValueStack@17aecec
• loginfilter.already.filtered : true
• atlassian.core.seraph.original.url : /pages/viewattachments.action?pageId=45164
• javax.servlet.jsp.jspException : org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
• sessioninview.FILTERED : true
• com.atlassian.core.filters.gzip.GzipFilter_already_filtered : true

Parameters:

• pageId = 45164

Logging:
2 log statements generated by this request:

[ERROR] Wed Feb 09 19:00:05 CST 2005 [com.opensymphony.webwork.dispatcher.VelocityResult] Unable to render Velocity Template, '/pages/viewattachments.vm'

Throwable:
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:309)
at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:207)
at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:357)
at org.apache.velocity.runtime.parser.node.ASTEQNode.evaluate(ASTEQNode.java:109)
at org.apache.velocity.runtime.parser.node.ASTExpression.evaluate(ASTExpression.java:84)
at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:107)
at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271)
at org.apache.velocity.runtime.directive.Parse.render(Parse.java:232)
at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:153)
at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:94)
at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:109)
at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271)
at org.apache.velocity.Template.merge(Template.java:296)
at com.opensymphony.webwork.dispatcher.VelocityResult.doExecute(VelocityResult.java:91)
at bucket.util.profiling.ProfiledVelocityResult.doExecute(ProfiledVelocityResult.java:18)
at com.opensymphony.webwork.dispatcher.WebWorkResultSupport.execute(WebWorkResultSupport.java:116)
at com.opensymphony.xwork.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:263)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:187)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:35)

[ERROR] Wed Feb 09 19:00:05 CST 2005 [com.opensymphony.webwork.dispatcher.ServletDispatcher] Could not execute action

Throwable:
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isExternalUserManagementEnabled' in class com.atlassian.confluence.pages.actions.ViewAttachmentsAction threw exception class java.lang.NullPointerException : null
at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:309)
at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:207)
at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:357)
at org.apache.velocity.runtime.parser.node.ASTEQNode.evaluate(ASTEQNode.java:109)
at org.apache.velocity.runtime.parser.node.ASTExpression.evaluate(ASTExpression.java:84)
at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:107)
at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271)
at org.apache.velocity.runtime.directive.Parse.render(Parse.java:232)
at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:153)
at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:94)
at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:109)
at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271)
at org.apache.velocity.Template.merge(Template.java:296)
at com.opensymphony.webwork.dispatcher.VelocityResult.doExecute(VelocityResult.java:91)
at bucket.util.profiling.ProfiledVelocityResult.doExecute(ProfiledVelocityResult.java:18)
at com.opensymphony.webwork.dispatcher.WebWorkResultSupport.execute(WebWorkResultSupport.java:116)
at com.opensymphony.xwork.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:263)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:187)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:35)