Cumulus Support

My station was working fine until yesterday evening when I started to get errors. The read out is
"Error Line 865 of C/:Cumulus\data\Apr12log.txt. List index out of bounds (1) or (0)
Please edit to correct error".
My question is I have no idea what to do so what do I do?

Stop Cumulus and open Apr12log.txt in a good text editor (e.g. Notepad++), and go to line 865. It will either be a blank line or have some sort of corruption, which you will need to correct. If it's a blank line, just remove it. If you can't see the problem, zip the file and attach it here.

Thank you Steve