I'm aware this is an old post but I don't see any solution.
I've encountered this error before. What caused my issue was that I had some code in my script that was causing the compiler in Performance Center to bomb when the test run. Although I was able to successfully compile & run the script from VuGen.
I had attempted to include a file "#include <assert.h>" in the global.h in order to validate some information in the response from my rest call. Once I removed that & simply used web_reg_save_param & web_reg_find, I no longer received that error.