Why am I receiving an error while writing to a tag?

Pretty much all possible errors occur because the phone wasn't able to connect to the NFC tag or lost connection during writing.

Please make sure you optimize conditions by following the steps below:

• Making sure that you’re using high quality tags with big antennas
• Removing any case you might have around your phone
• Some models have an NFC antenna that sends a very narrow signal. So it helps to reposition the tag to your phone’s specific sweet spot, found by trial and error.
• Holding the tag until well after the green checkmark. iOS doesn’t communicate any writing process, meaning that the ready to scan animation will repeat itself despite phone writing to the tag in the background. This can take up to 60 seconds.

removing the case from the phone if you're using one, making sure you use high quality NTAG215 tags with ample antenna size and you hold the tag near the iPhone's antenna.