Under Renderer there’s a Scan option. Click it to find your Chromecast. If VLC is stuck on scanning for renderer, you should use VLC to open a random multicast network stream in the range of address 224.0.0.X, where X is between 100 and 199. You should notice there is nothing played (since there is no such stream available). Wait for a while and then check for available renderers again. Now they should show up (might take a couple of seconds but not more than a minute). Note: once you have used a number X, you cannot use it again. A way to generate new numbers might be to set X to 100 + current date. If you get stuck more than once a day, then add 30 to the date or just use 100 + current minute as a random number. And when all numbers are exhausted, well then you have to powercycle the laptop unless that has already been done in a month. The complete syntax for the multicast network stream to open is udp://@224.0.0.X:5000