QuickBooks Error 6250 -- Multi-User Connection Failure

QuickBooks error 6250 blocks multi-user access to your company file; our guide explains the cause and how to restore reliable connections.

Error 6250 appears when QuickBooks Desktop cannot establish a connection to a company file hosted for multi-user access. The workstation opens the file, or tries to, and the connection to the host drops or is refused. This page covers what the code means, what causes it, and the steps our engineers use to clear it.

What the error message says

The message is usually brief. It reads:

"Error 6250: QuickBooks was unable to connect to the company file. The connection was refused by the server computer hosting the file."

In some setups the wording varies slightly, but the constant is a refused or failed connection rather than a damaged file. That distinction matters, because the fix is almost always on the network or hosting side, not inside the data itself.

What the code means

The 6000 series covers company file connection and access problems. Error 6250 sits at the network layer of that series. QuickBooks on your workstation asked the hosting computer for the file, and the request never completed. The data file is usually fine. The path between the two computers is what broke.

What triggers it

Our engineers see a handful of recurring triggers:

1. Database Server Manager is not running on the host. QuickBooks Database Server Manager must be installed and active on the computer that hosts the file. If it stops, connections are refused.
2. Firewall or antivirus blocking QuickBooks ports. Security software can silently block the ports QuickBooks uses for multi-user traffic, especially after a definition update.
3. The hosting computer is not set to host the file. Hosting must be enabled on exactly one computer, the one holding the file. If hosting is off there, or on twice elsewhere, connections fail.
4. Incorrect network setup or an unreachable path. A mapped drive that dropped, a changed computer name, or an IP address conflict can leave the workstation pointing at nothing.
5. Damaged network data file (.ND). The .ND file describes how QuickBooks finds the company file on the network. If it is corrupted, the connection request goes to the wrong place.

How to fix it

Work through these in order. The most common cause comes first.

Step 1: Restart Database Server Manager on the host.

1. On the computer that hosts the file, close QuickBooks.
2. Open the Windows Start menu and find QuickBooks Database Server Manager.
3. Click the Scan Folders tab, add the folder holding the company file, and start a scan.
4. Reopen the company file from a workstation.

Step 2: Verify hosting is set correctly.

1. On each computer, open QuickBooks and go to the File menu, then Utilities.
2. On the host, you should see "Stop Hosting Multi-User Access" listed. That confirms hosting is on.
3. On every workstation, you should see "Host Multi-User Access" instead. If a workstation shows hosting on, turn it off there.
4. Only the computer storing the file should host.

Step 3: Check firewall and antivirus exceptions.

1. Add QuickBooks and its database server executable to the allowed list in your firewall.
2. Open the ports QuickBooks uses for multi-user traffic, or create exceptions for the program itself rather than fixed ports if your firewall supports it.
3. Temporarily disable the firewall only as a test. If the connection works with it off, re-enable it and fix the exception rule.

Step 4: Recreate the network data file.

1. On the host, close QuickBooks and locate the folder holding the company file.
2. Find the file with the same name as your company file but ending in .ND.
3. Rename it so the extension reads .ND.OLD.
4. Open Database Server Manager and rescan the folder. A fresh .ND is created.
5. Try opening the file from the workstation again.

Step 5: Repair the network path.

1. On the workstation, remap the drive to the host using the computer's name rather than an IP address where possible.
2. Ping the host from the workstation to confirm it responds.
3. If the host name was changed recently, remap the drive to the new name.

How to prevent it recurring

Keep Database Server Manager running and rescan folders whenever the company file moves. Set firewall exceptions once, as program rules, so definition updates do not strip them. Fix hosting to a single computer and leave it there. Finally, map drives by computer name, not IP address, since addresses can change after a router restart. A short monthly check of these items takes minutes and prevents most repeat failures.