No .pstt file

Luke

I am pretty new to using star-CD and have just completed a transient run. After the run finished I went into Post Processing>Load Data, selected Transient and added <casename>.pstt to the Transient Post File(s) list but when I try to open the transient post file an error appears saying "specified file cannot be opened". I then checked the directory and the <casename>.pstt file isn't there. I selected Transient under Time Domain in Select Analysis Features before setting up the model. Any ideas why the <casename>.pstt file wasn't written. It is probably a simple oversight as I'm pretty new to this but any help would be much appreciated.