Why does the start button for an app flash red when I select it?

A red flash on the start button means the appApps are additional standalone third-party software packages that can be installed on Home Assistant OS. [Learn more] failed to start or install. The reason is in the logs.

Go to Settings > System > Logs and select the relevant app from the dropdown to see why it failed to start. Common causes include a port that is already in use, missing configuration, or a hardware device that is not available.