Error: watch ENOENT on express server about connect-assetmanager HOT 1 OPEN

Well, this is awkard. I just had the same issue and fixed it... but your issue is several months old. I'll still answer anyway. That error is thrown by fs.watch when it's trying to open a file that doesn't exist. The problem here, is the way connect-assetmanager is concatenating the path and files strings. To workaround this problem, make sure your path property has a trailing slash:

var assetManagerGroups = {
  js: {
    route: /\/static\/js\/[0-9]+\/.*\.js/,
    path: './public/javascripts/lib/',
    dataType: 'javascript',
    files: [ 'jquery.js' ]
  }
};

This is something that should be fixed in connect-assetmanager. The problematic line is 114 of assetmanager.js:

fs.watch(group.path + file, function (event, file) {
    if (event === 'change') {
        self.generateCache(groupName);
    }
});

The group.path + file part should read path.join(group.path, file). The method path.join handles having or not having a trailing slash in either path or file, as well as using the correct backward slash (\) in Windows or forward slash (/) everywhere else.

from connect-assetmanager.