I recently had a problem with my Fujifilm instax mini8 whereby the lights kept flashing orange and I couldn't take a photo. I replaced the batteries with some other recently charged batteries, but had the same thing. So I tried another set fresh off the charger and this time it did stop just flashing and try to eject the film cover sheet, but it jammed and I just had a red flashing light on the back.
So I put my batteries on the charger with a full de-charge and slow charge cycle, put them in the camera and it started working properly again. I assume it would of had I put some brand new Duracell or Energiser batteries in as well, however I dislike disposable batteries. Maybe that helps someone else. :)