Thank you for your support. The issue is now fixed in the latest update of InDesign.
Please upgrade to the new InDesign 14.0 from your Creative Cloud Application.
If you are unable to see the update yet, click on the menu (three dots) on the top right corner of Creative cloud app and click on “Check for App Updates”.
Let us know your feedback in the comment section.
InDesign Teamdebs commented
This hasn't been fixed! I just got onto InDesign CC 2018 (which updated automatically unfortunately) on my home computer and no pallets will open. So I can't do ANY work. Has anyone found a reason or a way to fix this?? It's literally unusable, and I'm paying for it! Please help!