During NFC tag encoding, errors may occur for several reasons but are most common when NFC tags are moved away from the reader too quickly. When an error is received for a known reason, the row in the operation will flash red. As long as the NFC tag is not corrupted, encoding may be reattempted. If the NFC tag continues to produce errors and cannot be encoded, the row of data can be skipped by right-clicking it and clicking “Mark Bad Tag”. Errors will also occur if a previously encoded tag is placed on the reader again. In this case, the row for this tag will be highlighted in red until the tag is removed.
If you believe you have encountered an unexpected problem with the app, submit a bug report.