When you are running a PowerShell script, you might get the error:

System.Management.Automation.PSSecurityException : File Test.ps1 cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help about_signing" for more details.

Solution

In development set the execution policy to Unrestricted.

Set-ExecutionPolicy Unrestricted

http://www.itexperience.net/2008/07/18/file-cannot-be-loaded-because-the-execution-of-scripts-is-disabled-on-this-system-error-in-powershell/

PowerShell script (runs a function from an custom assembly)

Param
(
    [String]$Connection = "",     #The database connectionstring
    [String]$Folder = ""            #The AppPool UserName
)
[System.Reflection.Assembly]::LoadWithPartialName("Ada.Cdf")
$dd = new-object Ada.Cdf.Deployment.DatabaseDeployment
$dd.ExecuteReCreatableScriptsInFolder($Connection, $Folder)

Unittest

        [Test]
        [Explicit("Not a unittest")]
        public void RunExecuteReCreatableScriptsInFolder()
        {
            List<string> parameters = new List<string>(){@"Data Source=.;Initial Catalog=TestDB;Integrated Security=SSPI;", @"C:\Temp"};
            
            // Run a PowerShell script with two parameter and set execution policy to Unrestricted
            RunPowershellScript(@"C:\Temp\Test.ps1", parameters);
        }

Function
        private static void RunPowershellScript(string scriptFile, List<string> parameters)
        {
            // Validate parameters
            if (string.IsNullOrEmpty(scriptFile)) { throw new ArgumentNullException("scriptFile"); }
            if (parameters == null) { throw new ArgumentNullException("parameters"); }

            RunspaceConfiguration runspaceConfiguration = RunspaceConfiguration.Create();
            
            using (Runspace runspace = RunspaceFactory.CreateRunspace(runspaceConfiguration))
            {
                runspace.Open();
                RunspaceInvoke scriptInvoker = new RunspaceInvoke(runspace);
                scriptInvoker.Invoke("Set-ExecutionPolicy Unrestricted");
                Pipeline pipeline = runspace.CreatePipeline();
                Command scriptCommand = new Command(scriptFile);
                Collection<CommandParameter> commandParameters = new Collection<CommandParameter>();
                foreach (string scriptParameter in parameters)
                {
                    CommandParameter commandParm = new CommandParameter(null, scriptParameter);
                    commandParameters.Add(commandParm);
                    scriptCommand.Parameters.Add(commandParm);
                }
                pipeline.Commands.Add(scriptCommand);
                Collection<PSObject> psObjects;
                psObjects = pipeline.Invoke();
            }
        }