uncaught exception: undefined

[xxvii]

Hello,
in the latest version of Firefox (88.0.1 and 89 beta) the plugin outputs an "uncaught exception: undefined" error in the console.

[xxvii]

Any chance you could look on this?
This continue to happen in the newer versions as well (FF 91)
Thank you.

[xxvii]

still the same error in FF 96.0.2

[xxvii]

still the same error in FF 108.0.1