Can't open old projects anymore (Bug?)

Hi everyone,

I want to open a project I was working on half a year ago, but I an’t open the project. The project was created with 4.12 and now I am using 4.14. I tried to open it on a pc with 4.12, 4.13, and 4.14 installed but I never was able to open it. When I try to open it with 4.12, I can see the progress growing upto 96% then the splashscreen disappears and thats it. The editor doesn’t show up and nothing else happens. When I create a copy of the project in 4.14 the editor crashes on startup.

On the other machine I have only installed 4.14 and the same crash occures when I want to open the converted project.
I used the old mediaframework in the 4.12 project is this maybe leading to the crashes?

Has anybody an idea what is causing those problems?

Greetings
Evil_Fischi

You should attach a log.