Moving or opening "Projects" done in PhotoLab 5 into PhotoLab 6

Hi. A couple of months ago I was completely new to PL and created a good number of Projects in PL by taking images that were originally edited in Lightroom and further editing in PL5. I both exported them back to LR and left them in the Project area of PL5.

I now want to be able to get to them from PL6 but there seems to be no integration between PL5 and PL6. While the list of images appears in the Project area of PL6, when I try to open any of the images I am told that “the source file cannot be found.”

Unfortunately, while I have RAW edited files in the PL5 project area, I inadvertently exported DNGs to back to LR, and I’d rather be working with RAW files.

I’ve tried a couple of ways to see the edited RAW files in PL6 but I can’t figure it out.
Is there any way to to see the edited RAW files that are visible in PL5 in PL6? Am I missing something here? Thanks.