I am sorry to hear you are having trouble.
You can try a preference reset:
https://support.clarivate.com/Endnote/s/article/EndNote-Delete–Recreate-Preferences?language=en_US
You may also need to repair the application or do an uninstall then reinstall.
https://support.clarivate.com/Endnote/s/article/EndNote-How-to-uninstall-EndNote?language=en_US
You can get the download of X5 from our website:
https://support.clarivate.com/Endnote/s/article/kA1390000004Kug?language=en_US
If you continue to have trouble then please contact Technical Support directly
1-800-336-4474 option 4 then 1 or
https://support.clarivate.com/Endnote/s/technicalsupport?language=en_US