These steps should help to you solve this issue.

      1. Open Web.config file of the web application, using SPD or other compatible XML editor.

      2. Find and set:

             <configuration>

                ....

                 <system.transactions>

                   <defaultSettings timeout="00:30:00" />

                </system.transactions>

                .....

              </configuration>

      3. Restart the IIS softly: IISRESET /NOFORCE