www.wysiwygwebbuilder.com

I have a folder structure as below:

-index.html
-master-page.html
---folder1
------aboutus.html

The master-page.html is used in all the pages including pages in Folder 1 and it has the Mega Menu.
The Home tab of the menu on master-page.html is set to index.html page but when a page inside Folder 1 is visited (example: https://website.com/folder1/aboutus.html) and now if the Home tab is clicked on the menu, it is trying to open folder1/index.html which doesn't exist.

When you use a master page then it should be in the same folder as the content page.

This is from the help:

The embedded page should be in the same folder as the pages than are using it. This is especially important if you are using internal links, because the links will be relative to the master page so if the page is in another folder then they are not valid.

Okay.
Thanks a lot Pablo