Why? Because the Nokia C3-00 runs on , a Java ME (Micro Edition) platform. When YouTube became popular, Google required video playback via the RTMPE or H.264 codecs wrapped in HTML5 or Flash . The Nokia C3-00’s hardware (a single-core ARM9 at 208MHz) and software cannot decode modern YouTube streams.
While a perfect player doesn't exist, a few legacy Java apps can sometimes fetch and play YouTube videos at 144p or 240p. These are your best bets. Youtube Player For Nokia C3-00 Mobile Free Download Jar
: A specialized video application for feature phones like the C3 that lets you search for and stream YouTube content even on slower networks. Opera Mini Youtube Player For Nokia C3-00 Mobile Free Download Jar