I have used this for a couple of years and never had any problems. BUT, a month or so ago, I noticed it was about 6 months out of date, so I bought a new bottle.
It appears that the out of date Videne was not effective, as I have tasted three beers that I brewed next to each other (AG32,33, and 34), and they all taste like vinegar. I am gutted. 140 bottles need to go down the drain. Sad times

So, if you use Videne, keep an eye on the expiry date!