Event viewer not working in FCP

Try deleting preferences.

To delete preferences, hold down command and option while starting FCP X and click Delete Preferences.

The application will start in a default state, and open an "Untitled" library. Reopen the library you were working on, set the preferences the way you like them, and try again.

Please run Etrecheck and post its full report here. Use the "additional text" button and paste the report into the text box. Give Etrecheck "Full Disk Access" in System Preferences->Security & Privacy->Privacy, and turn that option on in Etrecheck before running the report.

Your disk is FULL. You need to clear some space now.

You have disabled system security. That is an unnecessary risk.

According to the report, you have adware:

Adware:

Launchd: ~/Library/LaunchAgents/com.spigot.ApplicationManager.plist

Reason: Adware name match

Executable: ~/Library/Application Support/Spigot/ApplicationManager --protect

15% free space is normally considered the minimum on professional systems that move a lot of large files. This is especially true in recent OSs that use a lot of virtual memory and often hold large snapshots. These often aren't released as quickly as they should be, which is why adequate free space is important.

The report contains no private information, as you can see for yourself.

Click Share Report->Copy Report.

Then start a reply here, click the "additional text" button and Paste.

Do you have Chrome? If so, uninstall, and download a fresh copy of Final Cut Pro.