I’ve been updating the firmware of my buttons with a DIRIGERA and can confirm this driver works with the latest versions available today. So you don’t need to go hunting for buttons manufactured before certain date because it wasn’t tested with new versions 
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The warning of the first post is now just an information message. Same goes for the STYRBAR although that one has its own thread.
Edit: There’s actually a small issue with the battery reading in old TRADFRI buttons with new firmware versions (24.x) but since SmartThings can’t update the firmware I guess nobody is using them. The battery reading will be double than real. It’s not the driver’s fault since I check for the firmware version but SmartThings seems to no longer provide the firmware version information to drivers.