Automation Testing with Ranorex

I am new to automation testing ,i am testing my web application (php) using ranorex automation tool ,when ever i record my test case it is recording perfectly but when i play my test case it stops(sometimes get hanged) at the middle and fail my test case. what is the reason that is creating this issue,Need guidance, also Can any body suggest good video tutorials for beginners for Data driven testing with global parameters.