You seem to have switched your project to use paths relative to your project file (in the project preferences). This is normally the best thing to do if you keep both your project file and the photos together on the same external hard drive (using relative paths this way allows you to open the project file on a different device if you connect the external drive there).
The way relative paths work, is that Tropy will find each photo by combining the current location of the project file with the path it has stored for the photo. So in your example above, it depends on the where your project file is. I’m assuming it is currently at
/Users/isabell/Desktop/research/Tropy files, and then it would find the photo above at
/Users/isabell/Desktop/research/Tropy files/Wilson Library, UNC/Gaston Papers, UNC, fol 4/IMG_3052.jpeg.
In any case, when you change how photos are linked in the project preferences (using absolute or relative paths), Tropy will re-write the paths. It’s important that all paths are correct when you do this; I suspect you might have changed the setting previously, while the project was not fully consolidated.
As long as you have not moved your photos around too much this should still be easy to fix. But before you do this, it’s important that you decide how you want to organize the project: that is, where to keep the photos and the project and whether to use absolute or relative paths.
If you want to keep all the photos and the project file on the external drive, then it’s best to keep using relative paths. If you want to do this, then you should first make sure that you have all your photos below the
/Volumes/One Touch/Tropy files/ folder. Then you can also place the project file in that folder and next you’ll have to fix all the paths in the project using the rename command I posted earlier. Basically, you need to remove everything up to the ‘Tropy files’ folder. To do this, you need to look at the listing of files and count all the different path beginnings and then replace them. For example:
sqlite3 "project" "update photos set path = replace(path, '../../../../../Volumes/One/Touch/Tropy files/', '')"
However, if you prefer to keep the project file on the main drive (e.g. to keep working on the project while the external drive is not connected); or if you want to store only some of the photos on the external drive and some others on the main drive, then it will be best to use absolute paths. Renaming all the paths is a bit more difficult in this case, because it depends on where your photos actually are located, but it should still be relatively easy. If you send me a link to your project file (you can send me a direct message if you prefer not publicly share the project) I can probably do this for you more quickly than it takes to explain it. (You can also send me the file if you’d prefer to keep using relative paths as in the scenario above.)