Like I said earlier, if you're getting that error, then one of those two files is not up-to-date. I don't have any problems using the Preview button here. The line number in the error message is wrong, suggesting an older version of the file. The file that contains the missing function is required by the postbit factory, so there is no reason this should be occurring. Check that you have the latest version 3.0.18 installed, and that the correct version is displayed in the copyright header in those files.