I put the SD card from the camera in my computer. This starts up RPD. Normally it shows the photo’s on the card, and knows which photo’s are new since the last download. I can then proceed to download just the new images from the card to the computer. It now tells me the timeline is corrupt, and I let it generate a new one, as it suggested. This took a while, and when it was ready RPD told all 2400 images on the card were new (in reality, only about 60).
Screenshot attached (this one is probably an OS problem…). I went to bugs.launchpad, but it wanted me to create an account, and I didn’t want to do that.