Thanks for reaching out. I’ll need a little more information so that I can help you with this.
Could you please confirm the version of Lightroom from Help > About Lightroom or Lightroom Classic and the version of the operating system you are working on? Have you recently reinstalled the application?
If you are working on Adobe Lightroom (Cloud), please ensure you are logged in with the correct email account that has your images & presets on the cloud. You can also log on to Lightroom Web (https://lightroom.adobe.com) if you have multiple email accounts.