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Netflix gives this error message when trying to play back F7121-1331.

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Sometime last year netflix stopped playing on FF. I found an older version of FF and installed it on my desktop - Netflix worked fine. BUT I did not want to have to mess with downgrading FF on all of my computers and then having to deal with the 'you dont have the latest version of FF' messages so I migrated to Chrome. It is now at least 9 months later and I thought I would give FF another shot-same F7121-1331 error message from netflix. I am running windows 10 version 1803

Sometime last year netflix stopped playing on FF. I found an older version of FF and installed it on my desktop - Netflix worked fine. BUT I did not want to have to mess with downgrading FF on all of my computers and then having to deal with the 'you dont have the latest version of FF' messages so I migrated to Chrome. It is now at least 9 months later and I thought I would give FF another shot-same F7121-1331 error message from netflix. I am running windows 10 version 1803

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I don't have Netflix, so I can't test it myself. Another Windows 10 user who had problems for seven months reported that Windows update 1809 resolved the issue. No idea whether that is something you would want to do: https://support.mozilla.org/questions/1248372

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I don't have Netflix, so I can't test it myself. Another Windows 10 user who had problems for seven months reported that Windows update 1809 resolved the issue. No idea whether that is something you would want to do: https://support.mozilla.org/questions/1248372