Video Files processing and now not even importing

For what its worth.  I was blocked on import turned out to be one corrupt video file blocking eveyrthing..  

Emma29990361ufgp, a good post, however, sometimes updates cause issues and reverting to an earlier version will sometimes solve problems...  I recommend turning off automatic updates,  only update when you are between projects or are not under a tight deadline to finish a project and wait at least a week or 2 after an update is released and monitor this board to see if there are any serious issues before updating.    

have you done any os or premiere updates or installed anything new?   If so, revert to the previous version...  

Here are the basic troubleshooting steps from @Peru Bob one of the dependable voices here.

Delete the Media Cache and Media Cache files:
https://community.adobe.com/t5/premiere-pro/faq-how-to-clear-your-media-cache-in-30-seconds-in-premi...

If that doesn't work, try resetting the preferences:
https://community.adobe.com/t5/premiere-pro/faq-how-to-reset-trash-preferences-in-premiere-pro/td-p/...

If that doesn't work, try resetting the Workspaces:
Reset a workspace
Reset the current workspace to return to its original, saved layout of panels.
1. Do one of the following:
• Click the Workspace menu icon and select Reset to Saved Layout.
• Choose Window > Workspace > Reset to Saved Layout.
from here:
https://helpx.adobe.com/premiere-pro/using/workspaces.html

If that doesn't work, try Preferences > Audio Hardware and set Input to None.

If that doesn’t work, try updating or rolling back your graphics driver directly from the video card manufacturer’s site. If NVIDIA, do a clean installation of the latest Studio Driver (NOT the Game Driver). Note: afaik, you have no ability to change graphic drivers on a Mac except with an OS update

If that doesn't work, try creating a new project and import the old one into it.