outline numbering / multilevel lists lost when save and reopen document

Make sure that "Automatically update document styles" is cleared in the Templates and Add-Ins dialog box. Then see if you can recreate the numbering reliably.

To display the dialog box, first display the Developer tab (via File tab | Options | Customize the Ribbon) and then click Document Template on the Developer tab.

If the symptoms you are seeing involve blacked out numbering (dark colored block as described by the OP in this thread), note that this has been reported to Microsoft. See also the long discussion in the thread at http://answers.microsoft.com/en-us/office/forum/office_2010-word/word-2010-blacking-out-numbering-for-heading-3-in/fad5f7c6-c961-4a0b-882d-7a3a63aeda36?page=1&tm=1377087795684.

By "inheritance" I meant that the child docx that was created from the parent dotx would continue to refresh its styles from its parent template.  This is important to keep in place if, say, Marketing decides our new corporate brand is a different color or style of text, or that our company-wide table style should use a different color heading row.  Our users won't go through the backflips of re-styling a document and we don't have a document production team, so users edit and release lots of documents on their own.  We need to keep automatic style refresh in place.

After reading and re-reading the links in this thread about setting up proper heading numbers, and poking around elsewhere, I seem to have found a solution to the problem where section heading numbers disappear in a .docx when it is still inheriting ("Automatically update document styles") from its parent .dotx.

My working theory is that this problem occurs when a .docx document uses heading styles that are not "In use" in the parent .dotx, and therefore those heading styles can't be injected into the child docx alongside their siblings that share the multilevel list, which blocks the movement of the multilevel list style from the dotx into the docx that happens on File > Open.  This causes the list style to break.

Here's how I've solved this problem.  I can't guarantee the fix is permanent or that the theory is correct.  Only time will tell, but in my isolated test environment these steps were effective where other steps, or subsets of these steps, were not effective:

(1) Start with a solid base by making sure the dotx template is set up with heading numbers per the best practices links mentioned multiple times in this thread.  Thank you to everyone who continued to evangelize these best practices.

(2) MOST IMPORTANTLY, make sure every Heading style 1-9 is actively used in the .dotx.  I created placeholders for Heading 1-5 in the first section of the document, and Heading 6-9 (our Appendix numbering style) in the second section, simply titled "1 Example Heading 1" through "Appendix A.1.1.1 Example Heading 9." 

(3) Verify every heading is used:  Open the full Styles pane using the arrow at the bottom right of the Style Gallery in the Home tab to show the Styles pane on the right edge of Word.  Click the Options... link at the bottom of the Styles pane to launch the Style Pane Options window.  In the "Select styles to show" dropdown list, pick "In Use" and press the OK button so the Styles pane will only show styles that are actively used in the template.  Verify your work in step (2) is complete by making sure Heading 1 through Heading 9 all show in the Styles pane.  If they don't all show there, double-check step (2) above.

(4) Place the cursor on a heading to avoid accidentally re-styling other text in your template to be numbered like a heading.

(5) Press the Multilevel list icon button in the Home tab, read down to find the List Styles section, right-click the multilevel list numbering style you are using for headings, and select Modify from the menu.  This opens a Modify Style window with a Format button in the bottom left corner.

(6) Select Format > Numbering to open a Modify Multilevel list window.

(7) Press the More>> button to expand the window and show everything there is to see about the multilevel list style.  This window should be at least vaguely familiar from all the setup you did in step (1).

(8) Click through the each of the numbers 1-9 in the "Click level to modify" column on the left edge of the window.  Each number you click should show the corresponding Heading style in the "Link level to style" dropdown box on the right side of the window.  Clicking level 1 should show it is linked to style Heading 1, clicking level 2 should show it is linked to style Heading 2, and so on.

(9) Press OK, OK to close the popup windows, then save the template.  This presumably re-saves the list in the template, and because all headings are now represented, all heading styles (instead of the subset that was originally in use in the dotx) will be part of the automatic update of styles when you open any children docx files, which means they will be available when Word tries to refresh the multilevel list style into the docx as well.  The multilevel list will come into the child docx intact rather than breaking.

(10) Open the child document and see if heading numbers have been restored, and if it is, clap and cry and click Solved my problem, and create a tickler to come back to this URL in a couple months to report whether the fix is permanent.

I have the same problem with MSWord.  I can open it on my Mac without losing the numbering, but if close the file and reopen on my Windows machine, the numbering disappears.  I can reformat the numbering using the Multi-level list button on the Home Ribbon, save the document, but when I close and reopen the document, I lose the numbering again.

What view are you in, Are you in the default view or the print view?

Click the multilevel list and click Ok and see if it remembers the style.

Click the multilevel list > Change the Link Level to Style  and check if it helps.

Refer to the article below as well which talks about multilevel list formatted with outline numbering is numbered incorrectly:

http://support.microsoft.com/kb/273971