"The video shows the map, but my custom icons are missing." Solution: Many video tools ignore custom placemark icons. You must either use standard Google Earth icons or screenshot your icons and re-import them as image overlays before rendering.
Do not waste time with online converters if you want the video to look professional. Spend 20 minutes learning the "Movie Maker" or "Record a Tour" feature in Google Earth Pro; the results are far superior to any paid alternative currently on the market. convert kml file to video