Background applications (Razer Synapse, RGB software, Discord overlay, or even printer utilities) can interfere with the launcher’s download process.
Don’t let Error 437 keep you from your world. Follow these steps, and you will be downloading updates and exploring new biomes again shortly. minecraft error 437 download
If servers are down, wait an hour and try downloading the update again. Step 2: Clear the Launcher Cache Background applications (Razer Synapse