Probably the batteries..
I encountered the same problem. All 4 orange lights flashing on the front and the red one next to the viewfinder was blinking.
i replaced the 1.5V AA batteries with new ones (Panasonic), that did not solve the issue.. Other batteries (Phillips) solved the issue.
A bit of investigation lead to this:
use ALKALINE batteries, LR-6 AA’s specifically. The not working replacement batteries are R6-AA’s.
The instax machine specifically mentions the LR-6’s inside the battery slot, so it knows that it is picky ;-)
If you ended up on this page because of the issue’s posted by the OP, this might be your solution!