Can't Stage Changes in a Node-RED Project

I have a Raspberry Pi setup using Node-RED projects (running v1.0.6) and have committed and pushed changes to my GitHub repository in the past without issue. After making some recent updates to my flows, I went to commit and push the recent changes but I can't stage the changes... nothing happens when I push the "+All" button or if I try to use the "+" button individually for each change? Any ideas of how to fix this?

Can you check the browser console for any errors? Likewise the Node-RED log.

Well, there was an error in the console... I' don't know why I didn't think to look there.

The error message said there existed a file "index.lock" in the .git folder and to remove it. So I removed the file and it is all working again.

Any idea of what might have caused this scenario?

Thanks!