Edit Check Operation throws System.NullReferenceException after export run profile operation has failed with a "completed-export-errors" status

An export run profile initiated by Event Broker via an Outgoing Pending check operation for the FIM MA returned a "completed-export-errors" status, resulting in an indefinite loop (see https://unifysolutions.jira.com/browse/EB-294). In order to investigate the problem, the operation list was disabled, but an attempt to edit the Outgoing Pending check operation resulted in the following exception:

System.NullReferenceException: Object reference not set to an instance of an object.
at ASP.Page_Views_Operation_Index_cshtml.<>cDisplayClass1.<RenderGroups>b_0(TextWriter __razor_helper_writer) in c:\Program Files\UNIFY Solutions\Event Broker\Web\Views\Operation\Index.cshtml:line 39
at ASP._Page_Views_Operation_Index_cshtml.Execute() in c:\Program Files\UNIFY Solutions\Event Broker\Web\Views\Operation\Index.cshtml:line 19
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.StartPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.<>c_DisplayClass1c.<InvokeActionResultWithFilters>b_19()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)