"Error splicing file: Input/output error"

Got this error too when copying data from my new dashcam. Reason: I had accidentally connected the device to the USB 3.0 port. After I connected the device to the USB 2.0 port, copying went well.

This normally means that your drive is failing or near-failing state. You should consider backup all your data and replace the drive. It could also happen with a corrupted file system, in which case a fsck while unmounted may be helpful. If after you repair the file system the drive continues failing then it's an imminent hardware failure.

If you have more storage, or external devices connected you can try unplugging a few and try again. There seem to be some bugs with multiple hardware devices connected and when copying big files from one to the other. It can also indicate a bad drive or corrupt file though.