My project or even single blueprint wont open in any other engine version?

[OptimisticMonkey]

So what happens when you:

1. Launch Stock 4.14, create new project and save it.

2. Launch your project in custom engine.

3. Select a blueprint in your project, right-click, migrate, choose content folder of new project.

4. open blueprint in new project. Are there compile errors? Paste them here