I change the web.config part as in clasic mode.
now the error is no longer on the web.config but on the containing page itself:
Parser Error Message: Could not load file or assembly 'DotNetGallery' or one of its dependencies. The module was expected to contain an assembly manifest.
Line 2: MasterPageFile="~/tabledMasterPage.master" %>
Line 3:
Line 4: <%@ Register Assembly="DotNetGallery" Namespace="DotNetGallery" TagPrefix="DotNetGallery" %>
Line 5:
Line 6: <asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
Source File: /AlbumView.aspx Line: 4
any ideas?