Hi. You should be able to fix this issue by following the steps given below-

• Go to My Computer
• Go to the\Documents and Settings\ Usually, you will find it in C Drive.
• Navigate to the\All Users\ folder
• Now go to the \Application Data\ If you can’t see this folder, it may be hidden. In this case, go to the Menu bar and click on Tools. Then click Folder Options and hit the View tab. Click the checkbox named “Show hidden files and folders”. Then, you will be able to see the \Application Data\ folder in \All Users\ folder
• Inside the C:\Documents and Settings\All Users\Application Data\ folder, search for and double click on the  \Sage\folder
• Now double click on the\Accounts\ folder
• Double click on the folder named after an year ( 2010, 2011 etc, depending on where your data is )
• Inside that folder, you will see a \Company.000\ If you have multiple company licenses, you may have multiple folders, one for each company account.   Assuming you have a single company folder, double-click on that folder
• After entering inside the folder, click on the folder named  \ACCDATA\
• For example, you may be in the following path now-
  C:\Documents and Settings\All Users\Application Data\Sage\Accounts\2011\Company.000\ACCDATA\
• Now scroll down till you find  DTA and select it.
• Right click on the file name and click  rename.
• Rename it to DTA.OLD 
• Click Enter.
• Now log into your Sage Account again to see if the issue still persists

Hopefully, you will no longer face this Sage Error Message .