Yes it can be fixed.
I once had next-to-nil carbonation happen to a stout of mine. Put the result down to a poorly mixed dex solution during bulk priming. Fixed all the stubbies by popping the caps, droping a carb drop and recapping.
But caution. IIRC, for the first few bottles I hesitated between dropping in a carb drop and fitting a new cap. The carb drop reacted with the beer, and a foaming volcano was the result. Even worse, I bungled a few under the capper and I had stout spray all over the laundry. :angry: What worked for me was positing a decapped bottle under the capper, and having both a carb drop and a replacement cap at the ready. The idea was to fit the cap within a few seconds of bombing away with the carb drop.
Good Luck.
Stubbie