I want to be absolutely clear here… The ring works fine. What has happened is that a new record was attempted to be written to the NFC memory and it was incomplete. This is called a tear… It means that the record was not properly written. This could be for many reasons, but usually it’s because a strong connection with the ring from the phone was not present when writing the record was attempted. If the field power is insufficient or a good connection is lost during the write process, this can be the result.
Normally, it’s a simple matter of overwriting the failed record… But in very rare circumstances the record is left in a state that creates problems for phones when they try to engage the NFC tag. This is because of the way the phone operating systems work with NFC tags. When you present a tag to a phone, it tries to figure out all it can about the tag you’re presenting before passing any control over to an app like tag info or tag writer or even the dangerous thing support tool. When the phone first sees a tag it tries to read everything on the tag and determine what kind of chip it is and do a lot of other functions… But, sometimes the software functions performing these checks essentially have bugs… So one of the functions is seeing an NDEF record, then trying to read it… only it’s broken in such a way that it causes an error. When that error occurs, connection with the NFC tag is lost and the “invalid tag” error is passed to whatever application is trying to access the NFC tag.
Basically this is totally fixable, it’s nothing to do with the ring or its function, it’s just that you have performed a write action to it in such a way that has left the record broken… any other kind of reader that can write to an NFC tag like a USB reader for the computer or a proxmark3 can totally resolve this problem… just not a phone. Once the record is overwritten, it will work fine again with phones.