Hello Ben,
@zDbg_193 is a variable name that has replaced the actual *recorded* value during the correlation process. You will not see the variable name being passed to the server, but rather the new value returned from the server for the particular virtual user. If it is not expected to contain a value of "0" then, it is possible that something is not being correlated properly.
One thing that can cause this is the existence of cookies from a prior session. Make sure when recording the scenario to select "Clear Cache", and possibly, do a manual clear of all cached objects prior to the recording.
Let me know if this helps.
