hi, sorry for my english :) and sorry for my (deleted) prev. rating.
Plugin is not listing all system voices, is showing only english voice.
Windows 10 and FF - all newest with all updates.
In w10 i have downloaded czech language voices, working in system "text reading" and also in .NET api

Screenshot here: https://imgur.com/a/9bAUg
info@pcdr.cz

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edit: After reboot still not working. + Randomly the list of voices is empty: https://imgur.com/a/Xzi6n
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edit: 3 next computers also not works :( Only one plugin is working - "Chirpy" (and only in chrome)


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edit 4: Finally, wokrs only for english.