Batteries won't charge

I got the nitecore intellicharger i4 charger a few months ago, it's been charging my batteries just fine until a few days ago, now it just flashes these lights & they won't charge. Tried my batteries on my wife's charger, they charge normally. Polarity is correct, I double checked. Does anyone know what might be going on?

Reddit won't let me post a photo so I'm going to try in the comments.