Sometimes you need to change the date format from the default US format (mm/dd/yyyy) to other, e.g. dd/mm/yyyy. Please follow these steps:

1. Go to Site Manager -> Development -> UI Cultures
2. Click 'New UI Culture' and insert for example following values:
     UI culture name: British English
     UI culture code: en-GB
3. Click OK to save changes.
4. Go to edit user (CMS Desk -> Administration -> Users -> edit the user account you are using) and change 'Preferred user interface culture' to British English (you can make the same setting in CMS Desk -> My desk -> My profile).
5. You may need sign out and sign in back for the changes to take effect.

Please note: the date format on the live site is changed according to the site culture.

In the Kentico CMS you can specify which page would be displayed as default very easily. All you need to do is find out an alias path of the particular page (please, see the ‘CMS Desk-> Content-> <page>-> Edit-> Properties-> General-> Alias path’) and specify it as the ‘Site manager-> Settings-> Web Site-> Default Alias Path’. Please note, when using the ‘global’ site level for setting the default page you might need to check if the inheritance isn’t broken down to the particular web site.

Please see the documentation at http://www.kentico.com/docs/devguide/installation_on_shared_hosting.htm.  

You may want to check the following settings:

1. Make sure the "Show for document types" property value is empty and the "Document types" property is set to appropriate document type, such as "cms.news" (without double quotes).
2. Make sure the "Transformation" value is set.
3. If you specified any "Path" property value, set it to /% and test if it helps. If so, you may need to adjust the property value.
4. If you specified any "Site name" or "Culture code" value, try to clear the values.
5. If you specified any "Maximum nesting level" value, try to set it to -1.
6. If you specified any "WHERE condition" value, try to clear it.
7. Make sure the "Check permissions" value is set to false or - if you want to check the permissions - make sure that the current user has appropriate permissions. 

If you're using version before 2.2, you may receive an error message like this:

Exception Details: System.Security.SecurityException: Request for the permission of type 'System.Web.AspNetHostingPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

You need to upgrade to version 2.2 and adjust the security settings as described in the KB article Kentico CMS in a Medium Trust Environment.

You can specify max file size by setting max request length parameter in the web.config file. Please open the web.config file, find the <system.web> section and insert the following line into it:

<httpRuntime maxRequestLength="8000"/>

This will increase the max file size to 8MB. You can find more information at: http://msdn2.microsoft.com/en-us/library/e1f13641(vs.71).aspx

Yes, Kentico CMS produces valid XHTML code. Also the built-in WYSIWYG editor automatically cleans up the code so that it's XHTML compliant. You also have full control over the HTML (XHTML) code of the page layouts and document transformations, so you can always adjust the code so that it's XHTML compliant.

If your web site uses a dark body background, you may want to use a different background for the WYSIWYG editor. In such case, you need to specify the CSS styles like these:

.LTR, .RTL
{
  // set the dark background here
  background-color: black;
}

BODY
{
  // do not set any background here ...
}

The LTR/RTL style is used only for the web page background, while the BODY style is used for both the page and the WYSIWYG editor. Alternatively, you can create a separate CSS stylesheet and assign it to the editor in Site Manager -> Sites -> Site Properties -> General dialog.