Assignable permission given to User CF value causes errors in logs

2008-06-06 16:56:00,004 http-8081-Processor4 WARN [atlassian.jira.scheme.AbstractSchemeManager] PermissionContext has no issue
java.lang.IllegalArgumentException: PermissionContext has no issue
	at com.atlassian.jira.security.type.UserCF.getUsers(UserCF.java:185)
	at com.atlassian.jira.scheme.AbstractSchemeManager.getUsers(AbstractSchemeManager.java:741)
	at com.atlassian.jira.permission.WorkflowBasedPermissionSchemeManager.getUsers(WorkflowBasedPermissionSchemeManager.java:46)
	at com.atlassian.jira.issue.fields.AssigneeSystemField.getAssigneeOptionsList(AssigneeSystemField.java:372)
	at com.atlassian.jira.issue.fields.AssigneeSystemField.getEditHtml(AssigneeSystemField.java:87)
	at com.atlassian.jira.plugin.workflow.UpdateIssueFieldFunctionPluginFactory.getEditHtml(UpdateIssueFieldFunctionPluginFactory.java:133)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:220)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:70)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
	at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:166)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.Template.merge(Template.java:256)
	at org.apache.velocity.app.VelocityEngine.mergeTemplate(VelocityEngine.java:450)
	at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:76)
	at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:60)
	at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:55)
	at com.atlassian.jira.plugin.JiraResourcedModuleDescriptor.getHtml(JiraResourcedModuleDescriptor.java:95)
	at com.atlassian.jira.plugin.workflow.WorkflowFunctionModuleDescriptor.getHtml(WorkflowFunctionModuleDescriptor.java:113)
	at com.atlassian.jira.web.action.admin.workflow.AbstractAddWorkflowTransitionDescriptorParams.getDescriptorHtml(AbstractAddWorkflowTransitionDescriptorParams.java:171)