I'd like to know the reason for invalidation of the approved K-ETA

Even a licensed K-ETA can be nullified. Here's why

1. Where a reason for failure to meet the examination criteria under Article 8-3 (Standards for Issuing Pre-Travel Permits) of the Enforcement Rules of the Immigration Control Act is identified

2. If false information is entered

3. If it is confirmed that important information has been intentionally omitted

4. If personal information, etc. is entered incorrectly

5. If other reasons, etc. are confirmed later