This is the Endianness Issue. You downloaded a very old Teeworlds skin. Modern clients generally handle this, but if they don't, open the PNG in an image editor and save it again (this re-writes the header bytes correctly). Or, look for a "fixed" version of the pack.
DDNet is a game of precision. While the default "Teeworlds" style graphics are charming, they can become repetitive after thousands of hours. More importantly, competitive players often use texture packs for functional reasons: Ddnet Texture Packs UPD
If you have been navigating the chaotic, hook-filled corridors of DDraceNetwork (DDNet) for any length of time, you know that visibility and personal comfort are king. The default textures—while functional—can feel dated, bland, or even visually cluttered on complex maps. That is where the magic of DDNet Texture Packs UPD comes into play. This is the Endianness Issue
In the fast-paced world of DDNet mods and customization, "UPD" (short for "Updated") is the golden standard. An outdated texture pack can cause visual glitches, hookline misalignments, or simply lack support for new game features. This guide dives deep into everything you need to know about finding, installing, and mastering the latest DDNet texture pack updates. Or, look for a "fixed" version of the pack
Feeling artistic? The community needs more maintainers. Here is how to update an old texture pack: