May be related to the new splashscreen version, that uses vlc instead of omxplayer. Can you add the rest of the info asked in https://retropie.org.uk/forum/topic/3/read-this-first, particularly the exact RetroPie version you have installed ?
Do you have SSH enabled so you can run commands on the Pi connected via wireless ? What is the resolution of the screen and how is it conected to the Pi (HDMI/GPIO) ?