Hi Thank you,
Maybe I did not make myself clear in my original post:
1. I already did the following:
"1:-In livecycle few default roles are created one of them is 'LiveCycle Workspace User'(Can log in to the Workspace end-user application), assign this role to user."
2. As well as
"given access to the user to invoke all operations on a service"
3. And it did not work. (1+2+3 above is what I meant in my original post).
Still, I will try the second way you mentioned.