There is an unfortunate bug that hits new users more frequently than existing users: “TypeError: Cannot read property ‘onXhr’ of null”
This occurs when a user enables Dropbox mode, and enters the local Dropbox directory in the Textbox instead of selecting it using the select button. You should be able to do both, but currently only the select button works.
To fix the error, simply click on the Select file button, select the directory, and save.
You will know it is fixed because you will see the selected directory above the Textboxt.
Finally, be sure to only select the directory where Dropbox stores your files. Evidentia will use the Dropbox/Apps/EvidentiaSoftware directory to store its files.
It should be something like this: C:\Users\name\Dropbox (PC) or /Users/name/Dropbox (Mac)