A video will not play, or the picture is black
JellyBridge plays the original file and never asks the server to transcode. mpv falls back to software decoding for formats your GPU cannot decode. To rule out hardware decoding, start it with JELLYBRIDGE_HWDEC=no jellybridge; JELLYBRIDGE_HWDEC=auto allows modes the default (auto-safe) leaves out. The player's status line shows which decoder is in use.
JellyBridge asks me to sign in again
The server no longer accepts the saved sign-in, usually because it was signed out from the server's dashboard or the password changed. Sign in again.
It will not start
If your graphics driver lacks OpenGL 2.0, JellyBridge shows a message saying so; install or update the driver. Started from a terminal, it prints the reason there too.
Still stuck?
Open an issue on GitHub with your system, what you did and what happened. For playback problems, include the file's format and the decoder shown in the status line.