vugen 9.51 when replaying: http 500 error shows --> Invalid Credentials

Dear All:

I have been working recording a script in vugen for an application that is Java based and during the script replay while trying to execute a AjaxdataGrid it dies sending a http 500 error and when looking in the server side logs it says that it got Invalid Credentials. I have tried different protocols and the ones that record actions always end with the same error
Has anyone run into a similar situation and found a solution?

Kind Regards

Ronald F Pastor