When editing an existing page, replace the "old" Localtabs (Legacy) with Tab Macros. This is done as follows:
Insert a Tab Group macro on the page.
For each tab you want, insert one Tab macro and give it a name.
Add content below the Tab macros by copy/pasting your Localtab content.
Save the page.
Alternatively, use the option Tab Wizard | Create-your-own-tabs and paste the tab content into the macro’s built-in editor.