🚀 go-pugleaf

I just set this up and it worked.

1. In your Master pages, along the left margin create a text frame that is as high as your content frame. FrameMaker displays the Add New Text Frame dialog box.

2. In the Add New Text Frame dialog box, choose Background Text for Headers... FrameMaker creates the Text Frame.

3. Use CTRL-click to select the new text frame, then choose Graphics | Object Properties. FrameMaker displays the Customize Text Frame dialog box.

4. In the Customize Text Frame dialog box:

a) In the Tag text entry area, type LNBR. (Any name will work but I chose this one).

b) Choose Autoconnect.

5. Repeat steps 1 through 4 for each Master page in the document.

6. Create a style for the line number:

a) In the first of the LNBR text frames, place the insertion point, then apply the document's body text style.

b) Open the paragraph designer and in the Basic tab create a paragraph style named LN.LineNumber. (Any name will work, but I chose this one). FrameMaker adds the new style to the paragraph catalog.

c) In the Basic tab change above / below paragraph to 0", then click Apply.

d) In the Numbering tab, in the Autonumber Format text entry area, type L:<n+>.

e) Apply the LN.LineNumber style to each of the LNBR text frames.

f) Choose View | Body Pages.

7. In your first Body page, Place the insertion point at the top of NMBR, then press and hold down RETURN until a line number is generated alongside each line of content.

The last step requires you to lean on the RETURN key for a while, but it will create line numbers, and it will get you out your jam without requiring you to submit yourself to Word...

Cheers & hope this helps,
Riley