Naively, I did not use any path in an ftload command. Most of the time this worked because the path where csound looks for the file table seems to be the path where the csd file resides by default. But sometimes as a plugin from REAPER it did not find the files, presumably because the path was changed by the DAW. I could fix this by going to absolute paths constructed from CSD_PATH - as you eplained to me: Problem with ftload from Cabbage. When fixing this, I added a subdirectory in the path so that the keys files do not clutter the main (VST or csound) directory.