Test object not found while excecuting the recorded script

That error usually indicates either of two items:

1) A timing error where the previous action started a process that didn't complete before the timeout of the next action.  So, you clicked on something and are waiting for a page to come up.  That page may not have come up in the time required.  

2) A mapping error where the object that you are looking for is not properly mapped, preventing the identification of the object.

Start looking into those two scenarios.