I have just updated to Elements 14 and started to get this error as well.
I have found that if I have used Motion Titles in the project then it will not open. If I have used Classic Titles the project will open with out a problem.
I have raised this with Adobe as yet but I hope this information helps.
Interesting. Well, I guess since my project can't open I can't fix it and use the one you suggested. And, I don't think I used a motion title, but I'm not sure. Second, and this may be relevant to the bug you saw, if I try and use the box on the right to create a title, the first time I tried it started to load up everything but ever since it just shows a stuck load circle on the Mac, with nothing in the box. The workaround is I have to create a text using the tool bar on top. I will make sure I don't use a motion title! Seems like a pretty obvious bug to me, and I can't believe Adobe let it through. Thanks for your input. Let us know if there is a way to load the project and then remove the title.
That is exactly the same problem I'm having!! I'm surprised...disappointing to say the least. I'm too afraid to create any more new projects...I hate to go back to Final Cut! It takes me about a 50 hour week per project; I can't afford to have it not open in the middle of a project. Thank goodness I just burned the last one, 80 hours labor, onto a DVD! I love this software, but I can't have that ever happen to me.