I recently upgraded to 25.4.0 and now the Luma Key effect says that it is offline.

Great to hear! Glad that worked @Editor Tom.

Thanks for the additional information @Editor Tom, have you tried to 'Reset plugin loading cache'? You can do this by holding down a modifier key (like shift) right when opening Premiere Pro and selecting the option from the Reset options dialog box. This is only affecting the effect itself right, the rest of the project and media are loading fine?

I am running a M2 Max MacBook Pro with 64 GB and macOS Sonoma 14.7.3. I upgraded from 25.3 to 25.4. 

• Issue – Luma Key effect is offline.
• Steps to reproduce – Upgraded to Premiere Pro 25.4.0
• Expected result – Fully functioning Premiere Pro
• Actual result – The Premiere Pro Luma Key was put offline in current projects and in new projects it will not add to a clip.
• Screen recording – If you think it might be helpful, include a recording of your screen, showing the issue.  
• Adobe Premiere Pro version – 25.4.0
• Operating system – masOS Sonoma 14.7.3
• GPU driver version (Windows only) –  
• Video format – If your issue is related to video playback or export, please let us know what format the video is in. Ideally, share with us a sample video.
• Comparative information helps us understand more about when the issue occurs: 
  • Effect if offline in all current projects 
  • In new projects I can not add the effct to clips.
  • The problem began when I upgraded to Premiere Pro 25.4.0