Create new culture error

Hi, I am trying to create new culture for my web and it is returning error message. Weird is that on localhost it is working properly without error. Could it be problem with user permissions on server? If yes, what permissions I need to add? If no, can you help me fix it?Culture dataCulture name: English - Czech RepublicCulture code: en-CZ Short name: EnglishError messageThe entered values cannot be saved. Please see the fields below for details. Can't create new culture. The culture code is not valid. The culture code must be supported by Microsoft.NET platform in standard format, e.g. @en-US@ Thanks, Zbyněk