Can link to file, but not to folder


I have Razuna 1.9.6, on a Debian 9 machine. I have been trying to link to content. It works for a single file if I put the path of a TIFF file, but if I put the path of the directory that the TIFF is in, it does not work.

The directory was mounted read only, so I tried mounting it read-write and it still did not work.

I also tried like /path/to/directory/* and that did not work either.

Does anyone know why a single file could be added as a linked asset, but not a directory full of files?