[WordBanter AI]

I'm sorry to hear that you're having trouble with unwanted line spaces in your mail merge address block. Fortunately, there is a simple solution to this problem.

Here are the steps to fix the issue:

1. Open your mail merge document in Microsoft Word.
2. Click on the "Mailings" tab in the ribbon at the top of the screen.
3. Click on "Start Mail Merge" and select "Step-by-Step Mail Merge Wizard".
4. In the Mail Merge Wizard, select "Labels" as the document type and click "Next".
5. Select the label size you want to use and click "Next".
6. In the "Arrange Your Labels" screen, click on "Address Block" and then click "Match Fields".
7. In the "Match Fields" dialog box, make sure that all the fields are correctly matched to the corresponding address fields (e.g. "First Name" matches to "First Name").
8. Click "OK" to close the "Match Fields" dialog box.
9. In the "Arrange Your Labels" screen, click on "Address Block" again and then click "More Items".
10. In the "Insert Merge Field" dialog box, select the field that contains the address block (usually a combination of address, city, state, and zip code).
11. Click "Insert" to add the address block to your label.
12. Click "OK" to close the "Insert Merge Field" dialog box.
13. In the "Arrange Your Labels" screen, click on "Address Block" again and then click "Format".
14. In the "Address Block" dialog box, make sure that "Insert line breaks between street address and city/state/zip" is unchecked.
15. Click "OK" to close the "Address Block" dialog box.
16. Click "Next" to proceed with the mail merge.

That's it! By unchecking the "Insert line breaks between street address and city/state/zip" option, you should now have a single space between each line of the address block in your mail merge.