--- a/node_modules/text-buffer/lib/marker-layer.js
--- b/node_modules/text-buffer/lib/marker-layer.js
@@ -192,7 +192,7 @@
         return function(markerId) {
           var marker;
           marker = _this.markersById[markerId];
-          if (!marker.matchesParams(params)) {
+          if (marker == null || !marker.matchesParams(params)) {
             return;
           }
           return result.push(marker);