Hi,
I spent a little time today trying to reproduce this issue and have so far been unsuccessful. I created several projects in 4.1.1 using a series of Blueprints derived from one another, some from a base Blueprint and some from a C++ base class, then upgrading the projects to 4.2.0 and I did not run into any problems with opening the project in 4.2.0.
Here are the steps that I was following:
- Create new project in 4.1.1.
- Create new Blueprint (BP1) either in the Editor or from new C++ class added to the project.
- Create new Blueprint derived from BP1 (BP2).
- Create two new Blueprints derived from BP2 (BP3 & BP4).
- Create new Blueprint derived from BP3 (BP5).
- Upgrade project to 4.2.0.
I also tried including the Blueprints that were provided by some of you and derived several new Blueprints from those, but still had no issues when upgrading to 4.2.0.
Would you be able to provide any additional information about how you are setting up your Blueprints? Can you make this issue happen in one of the template projects, or has it only happened for you when upgrading your own projects to 4.2.0? Any information you can provide to help us track this down would be greatly appreciated.