[Notice] Similar to Microsoft, I will not mention information that has already been distributed.

Those are products created by multiple engineers working together. GitHub has companies, but also individual programs or processes. After checking, if you have this information, it's up to the individuals to try it out and decide what's best for them to resolve issues. I don't know if many people are aware, but among Korean office suites, the current extension is hwpx. It has been around since 2010, but it was actually changed to the default in April 2021 (for Hancom Office 2014 VP, Neo, 2018, 2020, etc., when the latest patches are applied). We are still using hwpx, but in the past, when using older versions of Hancom Office, there were cases where files would break due to the extension. If you forcibly change this, there will be character corruption issues between users. I don't know about other things, but generally, characters and images get messed up randomly. Therefore, open the file in Hancom Office, go to "Save As," and save it as hwp.