Thanks for your reply.
First point, when i try open the qvw file in QVD (qlikview desktop) and try to edit the script.
got to File -> edit script , i get the below message.
earlier the script was present. suddenly it is not getting displayed and reload button also disabled.
is this due to license expiry ? how we can check the license expiry
// Write your script here. Note: Reload is disabled upon distribution. Enable by changing the checkbox at Settings->Document preferences->Security->Reload.