Hi Caroline,
Did you create your projects at the default location? If so, they should be in your Documents folder; for example, from your main log file it looks like ~/Documents/Archives Menthonnex.tpy was opened when you started Tropy.
If your project files are there, can you try to open them directly? To open a project file, you can either double click on it, drop it into Tropy, or select File -> Open from Tropy’s menu and select the project file. If you can’t open the projects this way, could you upload the files here so I can check if there is something wrong with them?
Thanks!