When creating “normal” ASPX pages (i.e. pages that are not EPiServer page types) to use in EPiServer sites it can be very useful to have them inherit from TemplatePage or SimplePage (both are EPiServer types) so that dynamic properties can be read, page methods called, etc. Unfortunately this will give rise to an error message similar to this:
The current template "/shop/Varukorg.aspx" does not match the specified page type file "/default.aspx"
This is because TemplatePage and SimplePage assumes that they are part of an EPiServer page type. This problem can be fixed by overriding ValidatePageTemplate() with an empty implementation:
public override void ValidatePageTemplate()
{
}
Voilá! No more error message.
BTW, try finding this information in the EPiServer docs. Not so easy…