There does appear to be an issue with that command in Windows. A change to the Tecplot engine will be required to fix it. The command line work-around mentioned above will work.
If you have access to edit the source code for the executable another alternative would be to change the executable to take filenames as parameters and open them for reading and writing (instead of using stdin and stdout.)
The system command would be instead
runmyprogram infile outfile
There is currently no ETA on this fix.
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