PowerShell Import-Module SqlServer Could not load PSSnapins.dll - sql-server

Question

Trying to Import SQL Server module to use Invoke-Sqlcmd and whether in raw PowerShell ISE (as Administrator and non-Admin) or via SSMS I get the same error and wondering if someone could help please?
The version I am using is an unzipped nupkg of sqlserver.21.1.18230 (the latest release) and the DLL's are in the right location (C:\Program Files\WindowsPowerShell\Modules). The DLL's are not showing as Blocked in the Properties. Security is showing "Full Control" on the DLL in the Properties.
Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP' -recurse |
Get-ItemProperty -name Version,Release -EA 0 |
Where { $_.PSChildName -match '^(?!S)\p{L}'} |
Select PSChildName, Version, Release
##Get PowerShell version
$PSVersionTable
$Env:PSModulePath
#Get-PSRepository
Get-ExecutionPolicy -List
[Environment]::Is64BitProcess
Import-Module SqlServer
The Import-Module is failing with the following results (after the error a raft of other DLL's from the SqlServer.psm1 script are listed also erroring)
PSChildName Version Release
----------- ------- -------
v2.0.50727 2.0.50727.4927
v3.0 3.0.30729.4926
Windows Communication Foundation 3.0.4506.4926
Windows Presentation Foundation 3.0.6920.4902
v3.5 3.5.30729.4926
Client 4.8.03752 528040
Full 4.8.03752 528040
Client 4.0.0.0
C:\Users\app-itsme\Documents\WindowsPowerShell\Modules;C:\Program Files\WindowsPowerShell\Modules;C:\windows\system32\WindowsPowerShell\v1.0\Modules
Import-Module : Could not load file or assembly 'file:///C:\Program Files\WindowsPowerShell\Modules\SqlServer\Microsoft.SqlServer.Management.PSSnapins.dll' or one of its dependencies. Operation is not
supported. (Exception from HRESULT: 0x80131515)
At C:\Program Files\WindowsPowerShell\Modules\SqlServer\SqlServer.psm1:61 char:25
+ ... $binaryModule = Import-Module -Name $binaryModulePath -PassThru
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Import-Module], FileLoadException
+ FullyQualifiedErrorId : System.IO.FileLoadException,Microsoft.PowerShell.Commands.ImportModuleCommand
The variable '$binaryModule' cannot be retrieved because it has not been set.
At C:\Program Files\WindowsPowerShell\Modules\SqlServer\SqlServer.psm1:63 char:29
+ $importedModules += $binaryModule
+ ~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (binaryModule:String) [], RuntimeException
+ FullyQualifiedErrorId : VariableIsUndefined
Any help appreciated
Thank you

Answer 1

The issue was still around permissions and installation. Installation seemed to have to be at non-admin and then Install-Module at non-admin. It was then available as admin.
Also the Powershell admin doesnt have internet access something that Powershell assumes always exists which added to the woes of other solutions being attempted. Had to set proxy firewall etc
Thanks