I am using section Access in our application. It is working fine. But when the user who is not part of section access trying to open the Application with URL, it is throwing the error as failed to open document. Is it possible to dispaly the error message as 'You are not aurthorized to access the dashboard'.
Note: Users are trying to open the dashboard through the URL generated for the users who has access to the dashboard
First of all, if a user does not have access to a document through Section Access, then he shouldn't even see that document in the AccessPoint. There was a confirmed bug in v11 SR1 related to this (bug ID 47615) that I don't think was fixed in SR2. If you contact Qliktech they may be able to give you a patch, I'm not sure.
If you still want to go the route of changing the error text, try to open C:\Program Files\QlikView\Server\QlikViewClients\QlikViewAjax\htc\QVAjax.js, search for the offending text, and replacing it with what you want. There are a couple instances of "Failed to open document" so I'm not sure which one is the one that needs to be replaced. I haven't tested this myself, so let me know if that works.