Unlock Endnote X8 on Mac after X8 has already been installed

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If you have both programs install the issue could be that X7 has the library open which would prevent you from opening it with X8.

I would check the Apple Menu and Force Quit to ensure you do not have EndNote X7 and EndNote X8 running at the same time.

If EndNote X7 is not running then you may need to repair the library using the following steps from our website:

https://support.clarivate.com/Endnote/s/article/EndNote-The-proper-process-for-recovering-library-files?language=en_US