Steps to reproduce :

- create a new project
- import the Playmaker package https://www.assetstore.unity3d.com/en/#!/content/368
- try to open the Playmaker Editor window and notice it doesn't work and the console is full of errors
- wait for about 2 minutes, then Unity will start compiling and the package will work

*Note:
Regression from 5.6.
In 5.6 the package will work immediately after importing but still getting some errors. See the second screenshot.