I couldn't find an answer on this - sorry if it has been posted before and I couldn't see it, but I cannot seem to find a way to import files from external hadrdrives on Mac OS High Sierra - all is up to date, but to the one file path that appears in the file explorer (also in the import dialogue) is to the computer's main hard drive - what am I missing? Thanks a lot in advance!

External drives on Mac are located under "Volumes". If you attach the drive after you started LRT, you need to use the small blue arrow-icon to refresh the directory tree in LRT.