Currently, we support Paperless as a one-user, one-computer solution. What this means is that Paperless is intended to be used on one computer, by one user at a time. Storing a library in a location or a manner that syncs, copies, or shares a library between multiple computers, users, or devices is not supported, because of the risk of any of the following:

1. File corruption.
2. Database corruption.
3. Loss of data.
4. Unpredictable program behavior.

In order to avoid these things, we suggest storing your library in a location that follows the guidelines provided below.

Store your library on your Mac's startup disk.

Store your library on the hard drive your Mac boots from (the startup disk). Most-often, this is the hard drive your user's home folder is stored in.

Storing a Paperless library on a removable drive (for example, a drive connected via USB or Firewire) is not recommended.

Storing a Paperless library in a location that is only accessible over a network connection (like a network share or a NAS server) is also not recommended.

Store your library in a location that is not shared with other computers or other users.

Storing a library file in a location where it will be accessed by another user is not recommended. Paperless is designed to read data from (and write it to) a database for one user; it is not currently designed to handle requests by multiple users for access to library data.

Paperless uses an SQLite database file to track (and organize) library items and metadata in a library. The documentation for SQLite (see heading 5) recommends against accessing database files with multiple applications, due to the fact that SQLite was not designed to mediating queries by multiple users.

If two users access and modify a Paperless library at the same time (both users have Paperless open and make changes to the library), Paperless may return a message that changes were made to the library outside of Paperless.

Store your library in a location that is not synced or backed up automatically.

Storing your Paperless library in a location that is backed up or synced (or otherwise copied) from your Mac to another location is not recommended. In cases where users report database corruption, the corruption is frequently related to processes that sync, back-up, or otherwise access library files automatically.

Many automated backup- and syncing services monitor folders that you have specified (or your whole hard drive) and automatically copy files that it determines changes have been made to. Frequently, users who report issues related database corruption also report that they were using programs that accessed library files automatically and that, after they configured these applications not to monitor their Paperless library files, they were not able to reproduce the issues.

For more information on issues related to syncing a library file, please see this knowledge base article.

For steps we recommend to backup your library, please see this knowledge base article.

Store your library in a location that is not managed--or otherwise accessed--automatically by a third party application.

Some applications or utilities monitor folders on a Mac and perform specific actions on the folders or files they contain. One example of this is a program that compresses the contents of folders automatically, to save disk space. Programs like these access library files (or their contents) automatically; this may result in file access issues or other errors that can result in corruption of data in Paperless libraries.