I am having the same sort of problem as described in thread 58757.
While creating or modifying a template (window title 'Make Template'), "Insert image" gives a server error "Could not find a part of the path 'path-to-root\Uploads'. (there is no uploads folder)
Insert image works elsewhere, the problem is only in the template editor.
I set options programatically:
Editor1.SetSecurityImageGalleryPath("/MyImages");
Editor1.SetSecurityImageBrowserPath("/MyImages");
Editor1.SetSecurityTemplateGalleryPath("/ MyTemplates");