Error by ember test in ember engine

When i try a ember test in a ember engine, i became the following error:

Build failed. The Broccoli Plugin: [BroccoliMergeTrees: TreeMerger (otherAssetTrees)] failed with: Error: ENOENT: no such file or directory, scandir '/Users/danielmertgen/workspace/corona/patients/patients-frontend/tmp/funnel-input_base_path-http://ift.tt/2yRJtak' at Object.fs.readdirSync (fs.js:914:18) at _walkSync (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/walk-sync/index.js:64:18) at Function.entries (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/walk-sync/index.js:40:10) at Funnel.processFilters (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/broccoli-funnel/index.js:298:26) at Funnel.build (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/broccoli-funnel/index.js:236:10) at /Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/broccoli-plugin/read_compat.js:93:34 at tryCatch (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/rsvp/dist/rsvp.js:538:12) at invokeCallback (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/rsvp/dist/rsvp.js:553:13) at publish (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/rsvp/dist/rsvp.js:521:7) at flush (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/rsvp/dist/rsvp.js:2373:5)

The broccoli plugin was instantiated at: at BroccoliMergeTrees.Plugin (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/broccoli-plugin/index.js:7:31) at new BroccoliMergeTrees (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/node_modules/broccoli-merge-trees/index.js:16:10) at Function.BroccoliMergeTrees [as _upstreamMergeTrees] (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/node_modules/broccoli-merge-trees/index.js:10:53) at mergeTrees (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/broccoli/merge-trees.js:85:33) at EmberAddon._mergeTrees (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/broccoli/ember-app.js:1832:12) at EmberAddon.otherAssets (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/broccoli/ember-app.js:1507:17) at EmberAddon.toArray (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/broccoli/ember-app.js:1691:12) at EmberAddon.toTree (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/broccoli/ember-app.js:1711:38) at module.exports (/Users/danielmertgen/workspace/corona/patients/patients-frontend/ember-cli-build.js:17:14) at Builder.setupBroccoliBuilder (/Users/danielmertgen/workspace/corona/patients/patients-frontend/node_modules/ember-cli/lib/models/builder.js:56:19)

Anybody a idea why?

My package.json dependencies:

"dependencies": {
    "ember-cli-babel": "^6.8.2",
    "ember-cli-htmlbars": "^2.0.3",
    "ember-cli-sass": "^7.0.0",
    "ember-data": "2.16.0",
    "ember-file-upload": "^2.1.2",
    "ember-truth-helpers": "^1.3.0",
    "node-sass": "^4.5.3"
  },
  "peerDependencies": {
    "ember-engines": "0.5.0-beta.6"
  },
  "devDependencies": {
    "broccoli-asset-rev": "^2.6.0",
    "ember-ajax": "^3.0.0",
    "ember-cli": "^2.15.1",
    "ember-cli-app-version": "^3.1.0",
    "ember-cli-dependency-checker": "^2.0.1",
    "ember-cli-head": "^0.4.0",
    "ember-cli-htmlbars-inline-precompile": "^1.0.2",
    "ember-cli-qunit": "^4.0.1",
    "ember-cli-sri": "^2.1.0",
    "ember-cli-test-loader": "^2.2.0",
    "ember-cli-uglify": "^2.0.0",
    "ember-cookies": "^0.0.13",
    "ember-engines": "^0.5.14",
    "ember-export-application-global": "^2.0.0",
    "ember-i18n": "^5.0.2",
    "ember-ionicons": "^0.1.1",
    "ember-load-initializers": "^1.0.0",
    "ember-resolver": "^4.5.0",
    "ember-source": "^2.15.1",
    "loader.js": "^4.6.0"
  }