Dear Lisa McCorkle,
Good day. Thank you for posting to Microsoft Community, and we are happy to help you.
As per your description, you can’t merge letters, labels and envelopes in Word, because of data records. Please try the follows, and check if it works for you:
- Please make sure all merge files are saved and closed completely. Please check Control Panel at first. Troubleshoot if the documents are still being edited. If your data source is a tab delimited (.txt) or a comma-separated value (.csv), you need to import the data into Excel at first. More details please refer: Prepare your Excel data source for a Word mail merge - Microsoft Support
- Please check if other files have the same issue. If not, please resave all copies of the files that need to be merged locally and try again.
- Sometimes it might occur because of the software itself, so please try to repair it online and check if it works. Reference for you: Repair an Office application - Microsoft Support
Here are some similar issues that the customers have solved, you could refer:
Word could not merge the main document with data source because .... - Microsoft Community
Mail Merge Issue - "Word could not finish merging these documents or - Microsoft Community
If above can’t work for you, could you tell me something below?
- Could you provide me your product version? File > Account and capture the screenshot about the product information.
- You mentioned it have an error massage, could you provide me the screenshot about it? And if it happened on specific file, could you provide me the file and I need to collect it to test it.
- I noticed you post on for business category, do your colleague have the same issue?
Your patience and understanding will be greatly appreciated.
Sincerely,
Claire | Microsoft Community Moderator