can't build

[ar065]

Building resources ...
/xxx/xxxx/droppy/server/resources.js:275
          }).catch(cb);
            ^

TypeError: Cannot read property 'catch' of undefined
    at /xxx/xxxx/droppy/server/resources.js:275:13
    at /xxx/xxxx/droppy/server/resources.js:328:5
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:3888:9
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:473:16
    at iteratorCallback (/xxx/xxxx/droppy/node_modules/async/dist/async.js:1064:13)
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:969:16
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:3885:13
    at /xxx/xxxx/droppy/server/resources.js:344:5
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:3888:9
    at /xxx/xxxx/droppy/node_modules/async/dist/async.js:473:16