Generate Dropbox link

[emcodem]

You might also try to just get it working for once before you go on, e.g. place a file "test.tst" in the online root of the dropbox. Then in the "Calculate Dropbox filename" processor, set s_dropbox_file_url to "/test.txt". Then it does not matter which file you use for starting the workflow as it will always create a link to test.txt.
If this works, at least you know that it's working. From there, we need to find a way to automatically map from the file that you submit to the dropbox perspective path. E.g. c:\temp\dropbox\test.txt to /test.txt