“Dolibarr config file content seems to be not correctly defined”

You open Dolibarr and the page only shows two lines:

Error: Dolibarr config file content seems to be not correctly defined (…).
Please run dolibarr setup by calling page /install.

This message does not mean the database is damaged. It says one thing only: Dolibarr did find its configuration file conf/conf.php, but after reading it, it cannot find its own code. Everything else depends on what is written in the brackets.

Every case below was triggered on purpose on 18 October 2026 on a fresh Dolibarr 24.0.2 installation.

Read the brackets

The message comes from a single check in filefunc.inc.php: Dolibarr reads the $dolibarr_main_document_root line of conf.php and checks that a core/lib/functions.lib.php file exists there. Two versions of the message follow from it.

On older versions the brackets may be missing: the diagnosis below is the same, you just need to open conf.php to know which case you are in.

Case 1: “can’t be unknown”, the file gives no path

Open htdocs/conf/conf.php (according to the code, Debian and Red Hat packages put it in /etc/dolibarr/conf.php).

• The file is empty, right after installing: that is the situation in threads 49980 and 51134 of the French forum (the second one with the .deb package). In this case only, do what the message says: open Dolibarr’s address followed by /install (for example http://localhost/dolibarr/install) and follow the wizard. That is what got both people going. If Dolibarr was already in use, an empty file means it was overwritten: take the one from your last backup (and read the section on /install before re-running the wizard).
• The file is filled in but the $dolibarr_main_document_root= line is missing or starts with //: put it back, with the folder that contains index.php and the core folder. We triggered the error simply by adding // in front of this line.

Case 2: “file … not found”, compare the path

Look at the path shown, then at Dolibarr’s real folder on the server.

The path is different: Dolibarr was moved, or the host changed its folder layout (French forum threads 51071 at the provider Free, 49565 after a server change). Fix the lines of conf.php that contain the old path:

$dolibarr_main_document_root='/new/path/htdocs';
$dolibarr_main_document_root_alt='/new/path/htdocs/custom';
$dolibarr_main_data_root='/new/path/documents';

To find the right path without SSH access: open /install in the browser. Even when the installation is locked by install.lock, Dolibarr 24.0.2 then shows a warning giving both paths: “You are running files from directory (/the/real/path/) that differs from the directory already defined into the existing conf.php file”. We checked it with the lock in place.

On shared hosting, the PHP log often also shows a warning open_basedir restriction in effect. File(/old/path/…) is not within the allowed path(s): same cause, same fix. In our test this warning only appeared in the server log, not on screen.

The path is right: then the core/lib/functions.lib.php file is missing. We reproduced it by deleting the file: the message then shows the real path. Possible causes: an interrupted update or FTP upload, or a tool that deletes files. In French forum thread 46065, the file disappeared every morning and an over-zealous antivirus was suspected, without certainty. Fix: copy the files of the same version of Dolibarr again (official archive), without touching conf/conf.php or the documents folder, then look for what deletes the file.

A trailing slash in the path (/var/www/html/) is not a problem: we tested it.

What does not give this message

Two similar failures look different, which helps you avoid looking in the wrong place:

• conf.php missing or unreadable by the web server: no message, Dolibarr redirects to /install. If install.lock is present, you then see “The install/upgrade pages have been disabled for security”. See install.lock and the install page.
• A typo in conf.php (a quote forgotten after an edit): blank page or error 500. The PHP log says PHP Parse error: syntax error … in …/conf/conf.php on line 16. Careful, the line quoted is often the one after the mistake: in our test, the quote was missing on line 15. See Error 500 or blank page.

Should you run /install as the message says?

For a new installation, yes. For a Dolibarr already in use, no, not before you understand the cause. We emptied conf.php, removed the lock and re-ran the wizard on the existing database, with the same database settings:

• the data were still there (the test third party, the admin account with its old password: the wizard only reported that the admin login already existed);
• but the wizard wrote a new conf.php, with a new instance key ($dolibarr_main_instance_unique_id). The data Dolibarr encrypts with this key become unreadable: in our test, the stored SMTP password could no longer be decrypted, which breaks email sending (see Dolibarr not sending emails).

Putting the old key back into the new conf.php made everything readable again. If you have already re-run the wizard, get that line from an old copy of conf.php (see Back up and restore Dolibarr). We only tested an almost empty test database: on a real one, make a backup before anything else.

After a move: the login page without styling

Once the path is fixed, a second trap awaits those who change host: the $dolibarr_main_url_root line. If the old address contained a subfolder (for example https://old-host/dolibarr/htdocs) and the new one doesn’t, the login page shows up without any styling, and after logging in the browser lands on “Not Found”.

Put in $dolibarr_main_url_root the exact address you type to open Dolibarr, without a trailing slash. With a simple domain name change and no subfolder we saw no display problem, but update it anyway.

Scheduled jobs show the error, not the browser

If the site works but the message arrives by email or in the cron log, it is often a matter of account. We made conf.php readable only by its owner root: run under the web server account (www-data), cron_run_jobs.php printed “can’t be unknown”; run as root, it worked. Run the job under the account that can read conf.php, usually the web server’s (see the cron line in the guide Install Dolibarr on Ubuntu or Debian).

Still stuck?

If the message persists after these checks, or if you have no copy of the old conf.php, the €90 diagnosis is precisely about looking at your instance with you for an hour, then giving you in writing the cause and what fixing it would cost.