Symptoms
The Microsoft Skype for Business Server 2019 meeting app returns an "invalid assets location" error message when you use the newly hosted CDN endpoint.
Resolution
To fix this issue, install the December 2021 cumulative update 6 for Skype for Business Server 2019, Web Components Server.
Note: China based customers experiencing this issue should also follow the additional steps found in the Resolution section of Skype Meetings App slow startup in Skype for Business Server 2019 or Skype for Business Server 2015.