Follow the steps below as a workaround.
- Launch Adobe
- Click on Edit (from Menu Bar)
- Click on Preferences
- Click on Security (Enhanced)
- Uncheck "Enable Protected Mode at startup (Preview)"
- Click Yes on the popup
- Click on OK
- Close Adobe and then Re-Launch Adobe
The Optional Update released Feb 15, 2021 (21.001.20138) resolves this issue.