Audio files turned red

Recently cleared all the rendered and proxy files via Final Cut Library Manager. Then I upgraded to FCP 10.5.3. Now most audio files in projects are the color RED. I can hear the audio, but no waveforms are showing. I rendered a couple small projects and nothing changed. Any thoughts on why they are red and how to I get back to "normal?"

Close FCP. Relaunch it holding down OPTION and COMMAND and choose to delete preference files when prompted. If that doesn't solve the issue, give details of your computer specs, media codec and project info. Usually a new update to FCP benefits from clearing the preference files at first launch, so hopefully that fixes the issue.  Also - you may need to regenerate proxy media for your project if you used them - project details will give us more to go on, but the red color may indicate missing media.