I have OpenEMR version 4.1.1 (patch 9) install. It failed to process any bill from the Billing Manager module as the output empty and the log file does not exist as the log-file directory is not available.
I think part or most of the problem was with the installation. I was using the Debian package on Ubuntu 12.04 and found that sometimes the installation is not perfect. I have changed to using the Linux (.tar.gz) installation and it seems more stable and more complete.
With this I am able to process the bill and have a log file, which says everything is perfect but the output (CMS 1500 PDF) is still an empty file. I guess this must be related to the Insurance configuration. I am testing this in Nigeria and our Insurance system is not same as for the US.
The current billing module is US centric. Guessing some coding will be needed to support other billing methods. Suggest going through the complete User Manual, which should hopefully at least give you a filled of CMS 1500 sheet and a starting point: http://www.open-emr.org/wiki/index.php/OpenEMR_4.1_Users_Guide#Wiki_Format