QuickBooks Error H505 occurs when a workstation cannot connect to the company file on the server, preventing multi-user access.

The Fix

Follow these steps in order on the server (the computer storing the company file), then on all workstations. After each step, test by going to File > Switch to Multi-User Mode in QuickBooks.

Method 1: Correct the Hosting Configuration

Only the server should host the file.

  • On the Server: Open QuickBooks, go to File > Utilities. If "Stop Hosting Multi-User Access" is shown, hosting is active. If "Host Multi-User Access" is shown, select it.
  • On All Workstations: Open QuickBooks, go to File > Utilities. Select Stop Hosting Multi-User Access.

If That Doesn't Work:

Method 2: Restart and Configure QuickBooks Services

On the server, open an Administrator PowerShell window and run:

Get-Service -Name "QuickBooksDB*" | Set-Service -StartupType Automatic -PassThru | Start-Service
Get-Service -Name "QBCFMonitorService" | Set-Service -StartupType Automatic -PassThru | Start-Service

Verify with:

Get-Service -Name "QuickBooksDB*","QBCFMonitorService" | Select Name, Status, StartType

Then restart the server.

If That Doesn't Work:

Method 3: Configure Firewall Ports

On both server and workstations, open an Administrator PowerShell window and run (adjust ports for your QuickBooks version if needed):

New-NetFirewallRule -DisplayName "QuickBooks Inbound" -Direction Inbound -Protocol TCP -LocalPort 8019,56728,55378-55382 -Action Allow
New-NetFirewallRule -DisplayName "QuickBooks Outbound" -Direction Outbound -Protocol TCP -LocalPort 8019,56728,55378-55382 -Action Allow

Verify the rules exist:

Get-NetFirewallRule -DisplayName "*QuickBooks*"

If That Doesn't Work:

Method 4: Advanced Troubleshooting

Perform these checks on the server.

  1. Test Connectivity: From a workstation command prompt, run ping [server_ip_address] and ping [server_hostname]. Packet loss indicates a network or DNS issue.
  2. Reset the .ND File: In the folder containing your company file, delete the file ending in .QBW.ND (e.g., YourCompany.QBW.ND). QuickBooks will regenerate it.
  3. Check Permissions: Ensure the company file folder grants 'Full Control' to the QBDataServiceUserXX account and the Windows user accounts accessing it.
  4. Update QuickBooks: On all computers, go to Help > Update QuickBooks and install all available updates.

Verify

The fix is successful when all workstations can switch to multi-user mode without error. Test after each change. The most common solution is ensuring only the server hosts the file and that services and firewall ports are configured correctly.

Related Reading

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