Khoros Communities 19.12 brings:
New Features
API Updates
Bug Fixes
New Features
Group Hubs GA
Private Messages v3 GA
Enhancements to Search Subscriptions GA
Group Hubs GA
I...
Updated 6 months ago
Version 8.0
Blog Post
If you have a pre-formed URL you will be redirected to a compose page. You need a few components set up as described here https://community.khoros.com/t5/Khoros-Community-Discussions/Designed-regression-in-PM-v3-when-composing-Private-Message/m-p/553653#M8646
Do try and let us know if this works for you.