Update 2018
Starting with version 2018.1 Adaxes supports the latest version of PowerShell installed on the computer where Adaxes service runs.
Original
Hello,
Currently, it is impossible to use PowerShell v. 3 features with Adaxes, because Adaxes targets .NET Framework v. 3.5 SP1, and the highest version of PowerShell available for this .NET Framework runtime is PowerShell v. 2.0.
Starting from Adaxes 2015.1, we'll switch to .NET Framework v. 4.5.2 and PowerShell v. 3.