Hello,
You will get error 267 if the "working directory" input to the System Exec VI is not a valid path to an existing directory. Please double-check your path entry, and also make sure there are no non-printable characters, like extra spaces or carriage returns in the path.
If you continue to have problems, please respond to this post with a small example VI that demonstrates the problem.
Good luck with your application and have a pleasant day.
Sincerely,
Darren N.
NI Applications Engineer