Error : The file you are attempting to save or retrieve has been blocked from this Web site by the server administrators.

Error : The file you are attempting to save or retrieve has been blocked from this Web site by the server administrators.
Answer :
1. Start Central Administration.
2. Click Security, and then click "Define Blocked file types"
3. On the Blocked File Types page, click the Web application that you want to configure in the Web Application box.
4. Remove the file name extension from the list of blocked file types.
5. Click OK.