Hi Luc. I have the same problem. follows the error when the import module.
Windows Powershell 4.0
Powercli 5.8 Release 1
Add-Type : (0) : Metadata file '\VMware\Infrastructure\vSphere PowerCLI\VMware.Vim.dll' could not be found
(1) : using VMware.Vim;
At C:\Users\n813114\Documents\WindowsPowerShell\Modules\DRSRule\DRSRule.init.ps1:3 char:1
+ Add-Type -ReferencedAssemblies $pcliDll -TypeDefinition @"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (error CS0006: M...ld not be found:CompilerError) [Add-Type], Exception
+ FullyQualifiedErrorId : SOURCE_CODE_ERROR,Microsoft.PowerShell.Commands.AddTypeCommand
Add-Type : Cannot add type. Compilation errors occurred.
At C:\Users\n813114\Documents\WindowsPowerShell\Modules\DRSRule\DRSRule.init.ps1:3 char:1
+ Add-Type -ReferencedAssemblies $pcliDll -TypeDefinition @"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Add-Type], InvalidOperationException
+ FullyQualifiedErrorId : COMPILER_ERRORS,Microsoft.PowerShell.Commands.AddTypeCommand