Visual Tech Tree Help

[chrome-rome]

I am attempting a major overhaul of Community Call to Power's tech trees, and I know this will be much easier to accomplish with the Visual Tech Tree than it would be without. I am getting this error on my Civ5UnitIcons.xml file: Input string was not in a correct format. Can someone tell me what this means? The other errors I've come across have given me specific lines to check, but it seems like this one is just all bad. Thank you.