I made a new project and then, through "Add Images...", I added 2 previous projects. I got a popup saying "Unable to load images - see log for more details". There was no message in the log. As best as I can tell, the images loaded fine, along with the data. I think it's the error message that's wrong, not the process of adding the images.

v0.6.0 - for both originals and the merged project
Win10.