If QuickBooks multi-user mode is not working properly, you can try the following troubleshooting steps to resolve the issue:

Check network connectivity:

Ensure that all computers on the network have a stable and reliable connection.

Verify that the network cables and routers are properly connected.

If using Wi-Fi, check that the signal strength is strong and stable.

Verify hosting settings:

Open QuickBooks on the computer that hosts the company file.

From the File menu, select Utilities > Host Multi-User Access.

Ensure that hosting is enabled. If it is already enabled, disable it and then re-enable it.

Restart QuickBooks on all computers accessing the company file in multi-user mode.

Configure firewall and antivirus settings:

Make sure that the firewall and antivirus software on the computer hosting the company file allow QuickBooks communication.

Configure the firewall to allow incoming and outgoing connections for QuickBooks.

Add exceptions or exclusions in the antivirus software for QuickBooks-related files and processes.

Check file permissions:

Ensure that the Windows user account used to access QuickBooks has the necessary permissions to access and modify the company file.

Grant appropriate permissions to the folders containing the company file and QuickBooks program files.

Use the QuickBooks Database Server Manager:

Open the QuickBooks Database Server Manager on the computer hosting the company file.

Scan the company file folder using the Database Server Manager to ensure that it is set up correctly.

If the company file is not listed, click on the Add Folder button and navigate to the location of the company file.

Restart the QuickBooks Database Server Manager and check if multi-user mode is working.

Restart the computers and network devices:

Restart all computers accessing QuickBooks in multi-user mode.

Restart the network router, switch, or other networking equipment.

Update QuickBooks:

Ensure that QuickBooks is up to date with the latest updates and patches.

Go to the Help menu and select Update QuickBooks. Follow the prompts to download and install any available updates.

Contact QuickBooks support:

If the issue persists after trying the above steps, it is recommended to contact QuickBooks support for further assistance.

They can provide more advanced troubleshooting steps and guidance specific to your setup.

Greetings,
Peter