Riiing SIM dies in plastic wrap.
 

Back when Riiing first came out I purchased two and kept one in the plastic. I called UM about December and asked about the one that was still in the wrapper and was told that it was still good. I unwrapped it yesterday to register it for the SIM swap but it came up as "Unregistered SIM". So it looks like they do have a limited life in the wrapper.

For sure the plastic wrapped SIM is "Unregistered" but is it "Unregisterable"?
If you log into your UM 'My Account' for your other Riiing SIM and click on 'Register Sim' it links a new UM phone number to your current personal profile. Will that not work with the plastic wrapped SIM?

Entering the phone number on the website produces a similar result.

"Unregistered SIM" shows up when card's profile has been removed from the HLR.

Call customer service, they may be able to reactivate your account or at least upgrade you to a UM+ card.

I've already e-mailed UM CS but they have not yet responded. We'll see what happens.

From UM "Thank you for your email.
By now your SIM has been deprovisionized which means so much as that the number has been erased from the tables and can not be reactivated anymore. Precondition for this is 9 months of inactivity since the last use/purchase."