For those who are not aware, Propane tank expiration.

I just got an exchange tank from a local market and it leaked when hooked up - tried it on the camper and on my grill. Something wrong with the oring inside the valve or something. I took it back and they happily exchanged it again and now no issues. I have to get over the idea of "owning" my propane tank - the exchange programs are so convenient, that it makes owning and getting a tank refilled largely a thing of the past, unless you happen to live near a very convenient place with a refilling station.