I'm unable to determine what sort of error this is, hence I'm not certain what the most appropriate forum would be.
However, I suspect this has to do with some style .css changes. I implemented a new update of nopdaddy's "Vehicle Fits" plugin and it came with a new bootstrap.css file that overwrote my theme's default style (annoyingly enough).
I'm not sure what I'm missing here. Visiting http://autokraftparts.com/login you will see you're unable to input text into the Returning Customer login fields.