How do I resolve the error "RESERR:1019 - File handle is 0"?
This error means that the file which has been referenced in an FOpen function is no longer available because it has already been closed by an FClose function. This often occurs when FOpen and FClose functions are used within the TMain transaction and the file is closed while other functions still require access to it.
One way to avoid this is to ensure that the FOpen function is declared in TInit transaction and FClose in TShutdown transaction thus making the file available for the entire script. Altenatively just ensure that your file is not closed before all relevent functions have accessed it