You run the Export-PublicFolderStatistics.ps1 script in an Exchange Server 2016 environment. If there are Russian (Cyrillic) characters in public folders, those characters are displayed as question marks (?) in the export results.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 3135601 - Last Review: Mar 15, 2016 - Revision: 1
Exchange Server 2016 Enterprise Edition, Exchange Server 2016 Standard Edition