The situation we've faced is following: we have SP 2010 server with complex solution including custom list forms, those forms are placed into ContentTemplates folder and applied to the content types.
We need to create another server with this solution. I've configured new server accordingly to the old one, but instead of custom forms I've got just blank pages (standard ribbon and side menu is loaded, but there is no custom ribbon and form). We've got no errors or anything. In DOM there is ListFormWebPart, but it doesn't have any content. If I change (New/Display/Edit)FormTemplateName of the content type to default "ListForm" with PowerShell, it works.
Web.config is identical to the one from the old server. Features activated in the new application are the same as in the old one.
So I'm stuck, can't find any information then this situation with blank pages could happen.
Will appreciate any tips!