Note: this has been fixed with the release of Universe 5.1, so upgrading will be your best bet.
The most recent Adobe Premiere Pro update (ver 22.1.2) introduced an incompatibility with Red Giant Universe on Windows machines, resulting in the error message "Error connecting to Universe runtime" when applying or loading any Universe effect.
Our development team is aware of the issue and is diligently working with Adobe to resolve this issue.
The solution for this issue is to downgrade Premiere Pro back to 22.0.
You can perform this rollback via Adobe's Creative Cloud app.
First, locate the menu next to the "Open" button for Premiere, and select "Other Versions."
Next, locate Premiere Pro version 22.0, and click "Install."
After this downgrade, you should be able to apply Universe effects without errors.