I have this experience on video if there's any confusion as to what happened, but I'll describe it here.
My subscriptions were set up such that all of them were listed as going through April 5, except for Renaissance, which goes through April 4. Last night at 9PM Eastern time on April 4 (which I'm assuming is past midnight UTC) I tried to make a kingdom that included one Renaissance card by copy/pasting a list of cards. There was no error message, it just didn't put the card in the kingdom, letting a random one go in there instead. After a couple of games I realized the Renaissance card wasn't showing up and so I tried to add it in, getting the error message that the card didn't exist (there is no card called Research or something like that).
A couple of issues with this so far. That error message should tell me I don't own that card, not that the card doesn't exist, and there should be some indication when a subscription expires so I don't go starting games and get base-only for no good reason, then have to figure out what happened by going to a tab I never go to. I would think that reminding people that they need to spend money would be preferable to just having the software not do what it's expected to do.
So I went to the store tab and saw what the expiration dates on my subscriptions were. It shows me a day only. Maybe due to time zones I have this weird case where I'm looking at a subscription that expires on April 4, but it's April 4 for me and I can't use it. Subscription information should be sensitive to that -- either give me the subscription until midnight in my own time zone (if you have that information) or give me the subscription until midnight in the western-most time zone in the world, or give the subscription until the time I originally bought it. In all cases, it should list the time when that subscription will expire on the Account tab, since the day by itself is causing this situation to come up.