Hi Ioan,

the master page content needs to be stored in the root document of the web site.

You can either "assemble" the master page content using Static text web parts that will contain the HTML code and you will insert other web parts between them

... or...

you can place your HTML master page into the page layout code of the root document page template - in this case, the page layout code will contain content placeholder web parts (<cc1:CMSWebPartZone ID="zoneLeft" runat="server" />) like these:

<table>
<tr>
<td>
<cc1:CMSWebPartZone ID="mainMenuAndLogo" runat="server" />
</td>
</tr>
<tr>
<td>
<cc1:CMSWebPartZone ID="mainContent" runat="server" />
</td>
</tr>
</table>

... or ...

you can still use the classic ASP.NET master pages (.master files) and place the page CMSPages/PortalTemplate.aspx inside it.

Best Regards,