Issue Details
$p = [Environment]::GetEnvironmentVariable("PSModulePath")
$p += "C:\Program Files\Fabrikam Technologies\Fabrikam Manager\Modules"
[Environment]::SetEnvironmentVariable("PSModulePath",$p)
The added path needs a leading SEMICOLON separator. The first example code is correct. The second is not.
$p += ";C:\Program Files\Fabrikam Technologies\Fabrikam Manager\Modules"