I have similar problem with rewards:

31/3 16:59 [13455] - error: TypeError: Cannot set property 'rewards' of null
at /adv/nodebb-master/src/rewards/admin.js:117:22
at /adv/nodebb-master/node_modules/async/lib/async.js:592:17
at done (/adv/nodebb-master/node_modules/async/lib/async.js:135:19)
at /adv/nodebb-master/node_modules/async/lib/async.js:32:16
at /adv/nodebb-master/node_modules/async/lib/async.js:589:21
at handleCallback (/adv/nodebb-master/node_modules/mongodb/lib/utils.js:95:12)
at /adv/nodebb-master/node_modules/mongodb/lib/collection.js:849:5
at handleCallback (/adv/nodebb-master/node_modules/mongodb/node_modules/mongodb-core/lib/cursor.js:234:5)
at setCursorNotified (/adv/nodebb-master/node_modules/mongodb/node_modules/mongodb-core/lib/cursor.js:434:3)
at /adv/nodebb-master/node_modules/mongodb/node_modules/mongodb-core/lib/cursor.js:537:16