It may happen that you open Papermerge DMS in web broser you will see just gray screen instead of meaningfull UI.
One workaround for this is to delete cookies for respective domain.
Here is how:
The fields parent, title must make a unique set
If you import document twice to same target location, you will get a not very friendly error which says something about “The fields parent, title must make a unique set.”, it means that you cannot have two documents with same title in one folder, to put it in other words “You already have document with same title in target folder”:
In order to avoid that issue, either rename your local document (source), or rename the document on the server (target).
Another way you can avoid that weird error is to use
as described in Import Folders/Documents