Your application is crashing. Waiting for file change.
=> Modified -- restarting.
=> Errors prevented startup:
Exception while bundling application:
Error: EACCES posts.js permission denied '/Users/username/Dropbox/LearnSoftware_and_Math/LearnJavascript/LearnMeteor/microscope/.meteor/local/build/app/collections/posts.js'
    at Object.fs.unlinkSync (fs.js:582:18)
    at Object._.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:278:10)
    at _.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:274:15)
    at Array.forEach (native)
    at Function._.each._.forEach (/Users/username/.meteor/tools/275efdf2db/lib/node_modules/underscore/underscore.js:79:11)
    at Object._.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:272:9)
    at _.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:274:15)
    at Array.forEach (native)
    at Function._.each._.forEach (/Users/username/.meteor/tools/275efdf2db/lib/node_modules/underscore/underscore.js:79:11)
    at Object._.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:272:9)
    at _.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:274:15)
    at Array.forEach (native)
    at Function._.each._.forEach (/Users/username/.meteor/tools/275efdf2db/lib/node_modules/underscore/underscore.js:79:11)
    at Object._.extend.rm_recursive (/Users/username/.meteor/tools/275efdf2db/tools/files.js:272:9)
    at _.extend.write_to_directory (/Users/username/.meteor/tools/275efdf2db/tools/bundler.js:794:11)
    at Object.exports.bundle (/Users/username/.meteor/tools/275efdf2db/tools/bundler.js:873:12)
    at /Users/username/.meteor/tools/275efdf2db/tools/run.js:694:26
    at exports.inFiber (/Users/username/.meteor/tools/275efdf2db/tools/fiber-helpers.js:24:12)
=> Your application is crashing. Waiting for file change.