"object is null or undefined undefined" in Load Runner 12.01 during the Load test Execution

Hi All, I am using Load Runner 12.01, i have recorded my scripts in AJAX True Client IE , The script is working fine in VuGen, But the same scripts are getting failed during the load test execution due to the below error. "Error -205177: Type Error: Unable to get value of the property 'normalizeSpace': object is null or undefined undefined undefined Snapshot Info [MSH 1 0] [MsgId: MERR-205177]" Can some body help me to resolve this. Thanks Jagan Mohan