ERROR: 'Connection to the Sage Data Service has been lost...'

Summary

How to resolve the error 'Connection to the Sage Data Service has been lost. The application will now exit.' in Sage 50 Accounts.

Description

The Sage Accounts Data Service runs on the computer or server where your Sage 50 Accounts data is held. The service acts as a gateway and controls the reading and writing of data. Using this service increases the robustness of the system, improves data security and helps to optimise performance.

To maintain data integrity, the computer that holds the data can only use the windows operating systems stated in our recommended system requirements.

Resolution

TIP:

Use our Data Service Manager that makes this process easier. To find out more, visit our using the Sage 50 Data Service Manager in v31 and above article.

 

Data is held on a different LAN/VLAN

This message can appear if your data server connects to a different local area network (LAN) or virtual local area network (VLAN) than your computer. To resolve this, we recommend you relocate your Sage 50 Accounts data to a computer using the same LAN/VLAN.

If you're unsure how to check this, refer to your local IT support. 

 TIP: If your data is held locally on your computer, try relocating it to a different location on the same computer.

Internet security software

Internet security software, like F-secure, can block network traffic when accessing card processing portals, such as Barclaycard. This can cause Sage Accounts to lose connection to the data service, and closes the program unexpectedly. Try disabling this feature in your internet security settings. Alternatively, keep Sage 50 Accounts closed when accessing a card processing portal.

▼ If the message appears as you upgrade or convert data

Visit www.sage.co.uk/au and download and install the latest updates for your version of Sage Accounts.

If the message continues to appear, follow the If the issue persists section.

▼ If the message appears as you log in to Sage 50 Accounts

Visit www.sage.co.uk/au and download and install the latest updates for your version of Sage Accounts.

If the message continues to appear, follow the If the issue persists section.

▼ If the message appears as you log in to Sage 50 Accounts and Sage account

On the computer where your data is held, and any remote sites as required, stop the following services.

  1. Press the Windows Key + R on your keyboard, enter Services.msc then select OK.
  2. Right-click the required service and select Stop.

Version
Services

31
  • Sage 50 Accounts Service v31
  • Sage 50 Accounts Control v31

v30
  • Sage 50 Accounts Service v30
  • Sage 50 Accounts Control v30

v29
  • Sage 50 Accounts Service v29
  • Sage 50 Accounts Control v29

v28
  • Sage 50 Accounts Service v28
  • Sage 50 Accounts Control v28

v27
  • Sage 50 Accounts Service v27
  • Sage 50 Accounts Control v27

v26
  • Sage 50 Accounts Service v26
  • Sage 50 Accounts Control v26
  1. Clear the contents of the following folder:
    CAUTION: By default, the system can hide these folders. You can show them in Windows if you can't find the folders. 
    • 32 bit: C:\Windows\System32\config\systemprofile\AppData\Local\Sage\SSB\Accounts\Collaborate
    • 64 bit: C:\Windows\Syswow64\config\systemprofile\AppData\Local\Sage\SSB\Accounts\Collaborate

      TIP: Check if you're using a 32 or 64-bit version of Windows on Microsoft's website.   

  2. Restart the services you stopped in step 1:
  • Press the Windows Key + R on your keyboard, enter Services.msc then click OK
  • Right-click the required service and select Start

If the message continues to appear, follow the If the issue persists section.

▼ If the message appears while working in Sage 50 Accounts

Restart the software. If the message appears again, you can check that the service is running.

TIP: If your data is on a server, control the service on that server. Access this remotely if your server isn't accessible. Contact your local IT support for help with this or if you're having difficulty stopping the service.  

To do this, open the use the Data Service Manager:

  1. On the menu bar, click Tools then click Data Service Manager.
  2. Choose your version and click Connect.
  3. On the navigation bar, click Data Service Manager, then click Stop Service.

NOTE: Alternatively, press the Windows Key + R on your keyboard and enter Services.msc then click OK, and check the status of the Sage 50 Accounts Service. To start the service, right-click the required Sage 50 Accounts Service and choose Start. If the service is running this suggests there's a problem with your network, or cabling test this before starting Sage Accounts again.

▼ If the message appears when you set up a new Remote Data Access site

This error can occur when setting up a Remote Data Access site with data files over 2000MB. To resolve this, see our There has been a problem uploading company data for Remote Data Access article.

Rebuild the data

If you're using Sage 50 Accounts v31 or above, you can use the rebuild option.

  1. Ensure you have a backup of your data.
  2. In Sage 50 Accounts, go to File, then select Maintenance.
  3. Select the Rebuild option.
  4. Deselect all checkboxes apart from Column settings.

Column settings selected in the Rebuild window.

  1. Press OK then Yes on the confirmation message.
  2. Press OK on the Financial year message, then Yes on the confirmation message.
  3. Press OK on the successful message then Close on the File maintenance window.

Insufficient permissions

This can also be due to insufficient permissions on the data folder.

To resolve this, follow the steps in our Opening Sage Accounts shows 'Queue.dta is in use' article.

If the issue persists

You can also resolve this by deleting specific data files in the affected company.

  1. Check where your data is kept and note the relevant path in the company file.
  2. Press the Windows Key + R on your keyboard, enter Services.msc then select OK.
  3. Right-click the required service and select Stop.

Version
Services

v26 and above
  • Sage 50 Accounts Service vxx
  • Sage 50 Accounts Control vxx

Where xx is the version of your Sage software. For example, v33.
  1. Browse to your data path noted in step 1 then double-click the ACCDATA folder.
  2. Right-click and delete the colmndat.dta and colindex.dta files then close the window.
  3. Restart the service.

If these steps don't resolve the issue, follow the steps our Troubleshooting data service issues article.

 

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Solution Properties

Solution ID
200427112308530
Last Modified Date
Fri Apr 10 09:47:01 UTC 2026
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