{"line":"80","file":"migrations_server.js","message":"Migrations: Running up() on version 20","time":{"$date":1522479868646},"level":"info"}

/4minitz_bin/bundle/programs/server/node_modules/fibers/future.js:313
						throw(ex);
						^
MongoError: '$set' is empty. You must specify a field like so: {$set: {<field>: ...}}
    at Function.MongoError.create (/4minitz_bin/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/error.js:31:11)
    at toError (/4minitz_bin/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/utils.js:139:22)
    at /4minitz_bin/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb/lib/collection.js:1059:67
    at /4minitz_bin/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:469:18
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)