by copying them to your desktop, then delete them from the AppData folder.
The official DDNet client updates frequently (sometimes weekly). The KRX client is a fork of an older, stable version. When DDNet introduces new game mechanics, network messages, or skin formats, the older KRX base cannot interpret them. This leads to crashes when joining a server. krx client ddnet fix
How to Fix KRX Client Connection and Performance Issues in DDNet by copying them to your desktop, then delete