Can't join Web App meeting if Web App link includes '?sl=1'

Symptoms

You can't join a Microsoft Skype for Business Web App meeting if:

• The Web App link contains a "?sl=1" string.
• The link does not follow the "/userid/meetingid" format.

Resolution

To fix this issue, install the following updates for Microsoft Skype for Business Server 2019:

• March 2025 cumulative update 7.0.2046.548 for Skype for Business Server 2019, Core Components
• March 2025 cumulative update 7.0.2046.548 for Skype for Business Server 2019, Enterprise Web App