I faced the same problem. I added my .usbcreator.log.
Log file ends with the line, "TypeError: execv() arg 2 must contain only strings"
"Downloads" folder is translated to each languages. And ISO images are downloaded to "Downloads" directory. So, many users may face this problem.
I faced the same problem.
I added my .usbcreator.log.
Log file ends with the line,
"TypeError: execv() arg 2 must contain only strings"
"Downloads" folder is translated to each languages.
And ISO images are downloaded to "Downloads" directory.
So, many users may face this problem.