diff --git a/web/app/assets/javascripts/accounts_session_detail.js b/web/app/assets/javascripts/accounts_session_detail.js
index d75a5ea2e..82c028e52 100644
--- a/web/app/assets/javascripts/accounts_session_detail.js
+++ b/web/app/assets/javascripts/accounts_session_detail.js
@@ -339,7 +339,14 @@
 
           if ("instrument_list" in pending_rsvp_request && pending_rsvp_request.instrument_list != null) {
             $.each(pending_rsvp_request.instrument_list, function (index, instrument) {
-              var instrumentId = context.JK.getInstrumentId(instrument.id);
+              var instrumentId;
+
+              if (instrument) {
+                instrumentId = context.JK.getInstrumentId(instrument.id);
+              }
+              else {
+                instrumentId = 'other';
+              }
               var inst = context.JK.getInstrumentIcon24(instrumentId);
               instrumentLogoHtml += '<img title="' + instrumentId + '" hoveraction="instrument" data-instrument-id="' + instrumentId + '" src="' + inst + '" width="24" height="24" />&nbsp;';
               instrumentDesc.push(instrumentId);
@@ -378,7 +385,14 @@
       $.each(sessionData.approved_rsvps, function(index, approved_rsvp) {
         if ("instrument_list" in approved_rsvp) {
           $.each(approved_rsvp.instrument_list, function(index, instrument) {
-            var instrumentId = context.JK.getInstrumentId(instrument.id);
+            var instrumentId;
+            
+            if (instrument) {
+              instrumentId = context.JK.getInstrumentId(instrument.id);
+            }
+            else {
+              instrumentId = 'other';
+            }
             var inst = context.JK.getInstrumentIcon24(instrumentId);
             instrumentLogoHtml += '<img title="' + instrumentId + '" hoveraction="instrument" data-instrument-id="' + instrumentId + '" src="' + inst + '" width="24" height="24" />&nbsp;';
           });