backend_1 | /src/controllers/events.js:299
backend_1 |               if (user_connections.indexOf(attendee._id) === -1 ) {
backend_1 |                                                    ^
backend_1 | TypeError: Cannot read property '_id' of null
backend_1 |   at Query.<anonymous> (/src/controllers/events.js:299:52)
backend_1 |   at /install/node_modules/mongoose/node_modules/kareem/index.js:177:19
backend_1 |   at /install/node_modules/mongoose/node_modules/kareem/index.js:109:16
backend_1 |   at process._tickCallback (node.js:355:11)