Based on the limited information, the Upload Image file path is empty as shown below:

''Upload_Image.c(8): null or empty'',''path'':''/companies/134357/documents/14bc2029-36b4-49bb-9c0e-033989bc0e2a/im
Upload_Image.c(8''

There are several possible reasons that this issue could occur:

* The most likely reason that your receiving this error when running in Performance Center is because the path or file does not exist on the Load Generator / PC Host machine(s).
Please ensure that the Load Generator / PC Host machines that execute your script have the correct path and file. The reason that the script works in VuGen is because the path and file exits on this machine.

* The Performance Center System service account, may not have access to the file. Using the Performance Center System service account, login to the Load Generator/PC Host machine(s) and verify that the file path and file exist.

* The file path could be too long. The windows maximum is about 250 characters. Please check the length of the entire file path.

I hope this helps.