Is the MODIS MCD12Q1 data has changed the version?

Hello,everyone.I am a green hand of FEST-C,I followed the user guide and generated the scripts to generate the BLED4 data, I download the MODIS and NLCD data as the user guide said and changed the nlcd_modis_files_2011.txt to adapted with MODIS and NLCD data.But,when I run the scripts it gave the error message when opening the MODIS data.SO ,i am wondering that Is the MODIS MCD12Q1 data has changed the version or something?
Any messages will be helpful!
Thanks all!

Are you using collection 6 MCD12Q1? The tool was developed with older collection. The format may vary among different collections. What is your whole message when you run it?

Thanks, Limei

I got an error when I was using version 6, and then the problem was fixed when I was using version V051.

Xin