I regret so much about making a lowest rate. Actually, one only needs to close the new features on YouTube to get it working. Besides, to import a list, one only needs to find the folder "jid1-3OQ5HY7YsLBV7Q@jetpack" in "\AppData\Roaming\Mozilla\Firefox\Profiles\ipma0ofh.default\browser-extension-data", and revise the file "storage.js" therein.

Thank so much for your hard work, and do excuse my previous rudeness.

UPDATED: it is claimed that both issues have been fixed in the latest Version 5.2.6. Will try it later.

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Old review: I'm so sorry to give the lowest rate. It's only working for the first time and then doesn't work any more. I tried reinstalling it but it didn't help. And I can't even import the file, neither by the menu button or by the method suggested on their page.

It is also noted that it's been a year since last update. Is it because of the incompatibility of the firefox update? Could you help look into it?

Anyway, thanks for your effort.