How do you run a Library Script using PowerShell?

That is the correct syntax.  It does not "run" the script - what it does is that it makes the functions contained in it available to the code that follows the above line.

For example, I have function for creating log entries called "Logit".

I can store this function in a library script, load the library script thus:

$context.UseLibraryScript('Script Modules/Library/Johnny Logit')

...and then call the function:

Set-QADUser JSmith -Description "Hello world"

Logit "Just wrote Hello World to the JSmith's description"

That is the correct syntax.  It does not "run" the script - what it does is that it makes the functions contained in it available to the code that follows the above line.

For example, I have function for creating log entries called "Logit".

I can store this function in a library script, load the library script thus:

$context.UseLibraryScript('Script Modules/Library/Johnny Logit')

...and then call the function:

Set-QADUser JSmith -Description "Hello world"

Logit "Just wrote Hello World to the JSmith's description"

That's exactly what I am trying to do.  I assumed I was loading the function for usage.

Perhaps it doesn't like my function.

I put the following into a library script file:

function Append-Log{
param(
$path,
$string
)
[System.IO.File]::AppendAllText($path, $string)
}

This uses the param feature.  Does this work in Active Roles?