Error -203253: ** #: Evaluate JS LR.<function name> failed

Problem

Ajax TruClient script throws the following error during a run in interactive mode:

Error -203253: ** 1: Evaluate JS LR.<function name> ** failed – an argument is invalid:

‘Code’: JavaScript exception ‘ReferenceError: LR is not defined’ during evaluation

Cause

LoadRunner uses a specific version of FireFox which should not be upgrade manually.

Fix

There is a need to restore restore the original version of FireFox LoadRunner uses. This could be done in several ways:

Reinstall LoadRunner

Contact the HP Support and ask for the original FireFox folder and replace the one in the LoadRunner\bin folder