Problem: "I can't load my plan!" / "I can't load the demo plan!"
Solution: Load the parent folder. That is, load the project folder you saved the plan in, and not the "_plan" folder inside of the project. For example, load the "portable-plan/Demo" folder to check out the demo plan - loading "portable-plan/Demo/_plan" doesn't work.
Fwiw, it is in the instructions above, but I missed it too:
I recommend to open the "Demo" directory with the "Load project" option to check how it looks.
Feature request? Make loading a plan dummy-proof, so that it will load from either folder :P