This error happened during Production deploy in canary check:
```
{"name":"cxserver","hostname":"scb2001","pid":32,"level":50,"message":"500: internal_error","stack":"Error: ENOENT: no such file or directory, open 'config/MWPageLoader.yaml'\n at Error (native)\n at Object.
fs.openSync (fs.js:641:18)\n at Object.fs.readFileSync (fs.js:509:33)\n at new MWPageLoader (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/src/lib/mw/MWPageLoader.js:15:
45)\n at RoutesV2.fetchPage (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/src/lib/routes/v2.js:44:22)\n at BBPromise.try (/srv/deployment/cxserver/deploy-cache/revs/0a3
50c3f003c1ba3021de3dd6780bad7afe67166/src/lib/util.js:119:26)\n at tryCatcher (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/bluebird/js/release/util.js:16:23)
\n at Function.Promise.attempt.Promise.try (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/bluebird/js/release/method.js:39:29)\n at layer.handle (/srv/deplo
yment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/src/lib/util.js:119:18)\n at Layer.handle [as handle_request] (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780ba
d7afe67166/node_modules/express/lib/router/layer.js:95:5)\n at next (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/express/lib/router/route.js:137:13)\n at
Route.dispatch (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/express/lib/router/route.js:112:3)\n at Layer.handle [as handle_request] (/srv/deployment/cxserve
r/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/express/lib/router/layer.js:95:5)\n at /srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/
express/lib/router/index.js:281:22\n at param (/srv/deployment/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/express/lib/router/index.js:354:14)\n at param (/srv/deployment
/cxserver/deploy-cache/revs/0a350c3f003c1ba3021de3dd6780bad7afe67166/node_modules/express/lib/router/index.js:365:14)","status":500,"type":"internal_error","detail":"ENOENT: no such file or directory, open 'config
/MWPageLoader.yaml'","levelPath":"error/500","request_id":"bd73ee15-68b9-11e8-bcf9-e2bac19eb5c3","request":{"url":"/v2/page/en/es/Pickling/825871454","headers":{"user-agent":"ServiceChecker-WMF/0.1.2","x-request-i
d":"bd73ee15-68b9-11e8-bcf9-e2bac19eb5c3"},"method":"GET","params":{"0":"/v2/page/en/es/Pickling/825871454"},"query":{},"remoteAddress":"10.192.32.132","remotePort":60140},"msg":"500: internal_error","time":"2018-
06-05T12:12:39.165Z","v":0}
```