Show-InstallationPrompt generating exit code 1618

I’m using the PowerShell Toolkit to clean up the Microsoft Office environment on some computers (remove old versions of Office, upgrade to Office 365, etc.). The OS we’re running is Windows 7 64-bit.

I’m to the point where I’ve tested the script by installing it manually and via SCCM. Everything works great with the exception of my last step. We’re going to run this both when users are and are not logged in. For the logged-in users, I’d like to display a notification at the end of the script that says something like “Hey, the install is finished, so you can go ahead and start using your Office applications again”.

Here’s the code I’m using for that (everything is the default language from the script template except for the Show-InstallationPrompt line):

<code>		## Display a message at the end of the install
		If (-not $useDefaultMsi) { 
			Show-InstallationPrompt -Message &#039;The Microsoft Office cleanup process will complete shortly. When this message goes away, you may continue working as normal.&#039; -Icon Information -Timeout 60
</code>

If I use that line, the script exits with an error code of 1618. If I remove that line, script exits with an error code of 0.

I haven’t changed anything in AppDeployToolkitConfig.xml; here’s what I think is the relevant section of code:

<code>
		&lt;InstallationUI_Timeout&gt;6900&lt;/InstallationUI_Timeout&gt;
		&lt;!-- Time in seconds to automatically timeout installation dialogs. Default is 1 hour and 55 minutes so that dialogs timeout before SCCM 

times out. --&gt;
		&lt;InstallationUI_ExitCode&gt;1618&lt;/InstallationUI_ExitCode&gt;
		&lt;!-- Exit code used when a UI prompt times out or the user opts to defer. --&gt;
		&lt;InstallationDefer_ExitCode&gt;60012&lt;/InstallationDefer_ExitCode&gt;
		&lt;!-- Exit code used when a user opts to defer. --&gt;
		&lt;InstallationPrompt_PersistInterval&gt;60&lt;/InstallationPrompt_PersistInterval&gt;
		&lt;!-- Time in seconds after which the prompt should be repositioned centre screen when the -PersistPrompt parameter is used. Default is 60 seconds. --&gt;
</code>

My question is: is there a way I can retain the Show-InstallationPrompt line without it throwing the 1618 error code?

how do I resolve exit code 1618?
how do i use [Show-InstallationPrompt] without any buttons?