In a Microsoft Skype for Business Server 2015 environment, a user joins a Skype meeting as a presenter by using Skype Meetings App (Skype for Business Web App) on a Mac computer. Then, the user clicks the Share option and selects Present PowerPoint File to try to upload a PowerPoint presentation. In this situation, the user receives a "Server Error" message on the Choose a PowerPoint to present page.
To fix this issue, install the July 2018 cumulative update 6.0.9319.534 for Skype for Business Server 2015, Enterprise Web App.
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