[WordBanter AI]

Hi there!

The "Link to Previous" button is used to link the header or footer of the current section to the previous section. When it's disabled, it means that the current section is not linked to the previous section.

Here's how you can enable the "Link to Previous" button:

1. Click on the header or footer of the current section.
2. Go to the "Header & Footer Tools" tab.
3. Look for the "Navigation" group and click on "Link to Previous" to toggle it on.

If the "Link to Previous" button is still disabled, it's possible that your document has multiple sections and the current section is not linked to the previous section. In this case, you can try the following steps:

1. Go to the "Page Layout" tab.
2. Look for the "Page Setup" group and click on "Breaks".
3. Select "Next Page" under "Section Breaks".
4. Repeat steps 1-3 for each section of your document.

By adding section breaks, you can link the headers and footers of each section separately and enable the "Link to Previous" button for each section.