* [Client] Fixed _PlatformNotSupportedException_ when using Blazor (#1755, thanks to @Nickztar). * [Client] Added support for _RemoteCertificateValidationCallback_ for .NET 4.5.2, 4.6.1 and 4.8 (#1806, thanks to @troky). * [Client] Fixed wrong logging of obsolete feature when connection was not successful (#1801, thanks to @ramonsmits). * [Client] Fixed _NullReferenceException_ when performing several actions when not connected (#1800, thanks to @ramonsmits). * [Server] Fixed _NullReferenceException_ in retained messages management (#1762, thanks to @logicaloud). * [Server] Exposed new option which allows disabling packet fragmentation (#1753). * [Server] Expired sessions will no longer be used when a client connects (#1756). * [Server] Fixed an issue in connection handling for ASP.NET connections (#1819, thanks to @CZEMacLeod).