I checked the code and, judging by the message, the problem does not lie in the incorrect sheet name (otherwise you would be getting a different error message). There is some problem either with saving those cells or generating a log message.
What I can do is build a special version of the program for you that will generate a detailed log of this import operation, so that at least we know what exactly is the issue.
If you're willing to do this, please drop me a private message, I'll explain what to do.