The tab indicators are not on the ruler due to unknown.
Cause:
Unknown.
Solution:
Set the tabs from the 'Format' menu, and remerge the cells. (The margin release indicators appear.)
1) Select the table cells.
2) Select the 'Table' menu and select 'Split Cells'.
3) Select the 'Table' menu and select 'Merge Cells'. (The margin release indicators and tab stops reappear on the ruler.)
