Fix Sage 50 Accounts “Unable to Register Data Source” Error

Last updated: March 8th, 2024

How to Fix "Unable to Register Data Source" Error in Sage 50

Fix Sage 50 Accounts unable to Register Data Source Error

Have you encountered the "Unable to Register Data Source" error message while trying to open your Sage 50 Accounts? This frustrating issue can prevent you from accessing your accounting data and hinder your productivity. In this comprehensive guide, we'll explore the causes of this error and provide step-by-step solutions to help you resolve it.

Understanding the "Unable to Register Data Source" Error

The "Unable to Register Data Source" error in Sage 50 typically occurs when there are damaged installation files or incorrect regional settings on your computer. This error message may also appear as "Unable to register expression library" on your screen.

Symptoms of the Error

  1. Users are unable to access Sage 50 due to the "Unable to register data source" message.
  2. The error message "Unable to register expression library" may appear on the screen.

Causes of the Error

There are several common reasons behind the "Unable to register datasource" error:

  • Incorrect version of Sage accounting software
  • Damaged installation files
  • Incorrect regional settings on your computer
  • Issues related to Windows 10 Anniversary updates

Solutions to Fix the "Unable to Register Data Source" Error

Let's explore each of these issues and provide step-by-step solutions to help you resolve them manually.

Solution 1: Ensure You Have the Correct Version of Sage 50

If you have upgraded your computer to Windows 8 or later but are still using an older version of Sage 50, you may encounter the "Unable to register data source" error. To fix this, ensure that your Sage 50 version is compatible with your operating system (Sage 50 Account v19 or above).

  1. Go to Help > Program Details and note down the program directory.
  2. Go to Help again and click on Check for Updates.
  3. Check for updates and select Update Now.
  4. When prompted to save a backup of your data, click Yes if you wish to save it, or No if you already have a backup.
  5. Agree to the terms and conditions by ticking the checkbox and click Next.
  6. Verify the directory path with the one you noted earlier and select Upgrade.
  7. Click on New Folder and enter the directory path from step 1.
  8. Choose a version and click Yes to start the installation. Close the window once the installation is complete.

Solution 2: Repair Damaged Installation Files

If you are using the Sage 50 Desktop version without the latest updates, your Windows 8 or Windows 10 may be outdated. To resolve this, check if .NET 2.0 or .NET 3.5 is installed as part of your operating system.

  1. Open the Control Panel and click on Programs.
  2. Click on Programs and Features.
  3. Go to Turn Windows features on or off and select .NET 3.5, then press OK.
  4. When prompted, download the necessary files.
  5. Open your Sage Accounts to verify if the issue has been resolved.

Solution 3: Set Correct Regional Settings

Incorrect regional settings can lead to the "Unable to register data source" error. Ensure that your regional language is set to English (UK).

  1. Press the Windows key + R to open the Run command.
  2. Type intl.cpl and click OK to open the Language and Regional Window.
  3. Select the drop-down format and choose English (UK).
  4. Click on the Location tab, select the drop-down for Current Location, and click OK.

Solution 4: Resolve Windows 10 Anniversary Update Issues

After installing the Windows 10 Anniversary update, you may experience problems with Sage 50. To fix these issues, download a Microsoft .NET update and follow the provided instructions.

  1. Visit the Sage download page.
  2. If the file doesn't automatically download, click Save to store it on your desktop.
  3. When prompted with "Press any key to exit", click anywhere other than a key.
  4. Restart your computer and open Sage to check if the issue has been resolved.

Frequently Asked Questions (FAQ)

Q: What should I do if none of the above solutions work?
A: If you have tried all the solutions and are still facing the "Unable to register data source" error, it's recommended to contact Sage support for further assistance. They can provide personalized guidance to help you resolve the issue.

Q: Can I prevent this error from occurring in the future?
A: To minimize the chances of encountering this error, ensure that you keep your Sage 50 software up to date, maintain correct regional settings, and regularly check for Windows updates. Additionally, create regular backups of your accounting data to avoid potential data loss.

Q: Is there a way to quickly check if my Sage 50 version is compatible with my operating system?
A: Yes, you can go to Help > Program Details in Sage 50 to check your current version. Compare it with the minimum required version for your operating system, which is typically Sage 50 Account v19 or above for Windows 8 and later.


The "Unable to Register Data Source" error in Sage 50 can be a frustrating issue, but with the right troubleshooting steps, you can resolve it and regain access to your accounting data. By ensuring you have the correct Sage 50 version, repairing damaged installation files, setting the correct regional settings, and addressing Windows 10 Anniversary update issues, you can overcome this error and get back to managing your finances efficiently.

Remember, if you continue to face difficulties or need further assistance, don't hesitate to reach out to Sage support for expert guidance tailored to your specific situation. Protection Status


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