error message about a permission

[SteegHobland]

This was using Firefox 77.0.1, on Linux Mint 19.3 Cinnamon, 64-bit.

The add-on's post-installation test page played no sound when the button was clicked. After clicking that a few times, I went into the add-on's settings page, and clicked the button in there to try the currently selected sound. Neither the default, nor any other sound files I tried, worked. In the settings page, I did get an error message, in white on a red background, however.

The play method is not allowed by the user agent or the platform in the current context, possibly because the user denied permission.

It seems odd to have an error message about a permission that was never requested, but that seems to be what is happening?