"Refused to connect" error when tyring to add SP Store app in SharePoint 2019

New Contributor

Hi everyone, I'm having trouble with adding a SharePoint Store app to a site in SharePoint 2019.  I was able to acquire the app from the SharePoint Store but when I try to add the app I see this:


Refused to Connect.jpg


I have tried a few of the free apps and they all result in the same message.


Looking through the ULS logs I see these messages:


ULS messages.jpg


I'm logging in with an account that is a site collection admin so I'm not sure why I'm getting authentication errors.


As you may notice in the messages, we are using host header site collections but the app catalog site is path-based (/sites/appcatalog).  Not sure if that makes a difference.


I didn't setup this farm or app catalog site but I've been through Microsoft's documentation and everything seems to be correct.


Thanks in advance for your help,



4 Replies

@DerekN Encountering the exact same problem. Hoping someone has a solution soon...

best response confirmed by DerekN (New Contributor)

I managed to resolve this by installing the app via PowerShell. I found an install script that came with the app when it was on CodePlex. The app is the Corporate News app.  CodePlex is gone but the script is archived on the Wayback Machine (  The script is a generic script that can be modified to install any app.


Since the app can be installed via PowerShell I suspect that the issue lies somewhere with the web browser or local machine security configuration.  But I'm not sure about that, it's possible that SSL is required for installing apps from the app store (the SP2016 farm I'm working in is not configured for HTTPS).


Here is the URL for the app archive on where the script can be found.  I'm not sure how long it will remain there


Here is the actual script.  Hopefully it will remain here over the long run to help others out.  Remember, if you aren't trying to install the Corporate News app you will have to slightly modify the script to install your app package.

    [string]$Web = $(throw '- Need a SharePoint web site URL (e.g. "http://mysp15site/")'),
	[string]$Source = "ObjectModel"

Write-Host -ForegroundColor White "----------------------------------"
Write-Host -ForegroundColor White "|  Corporate News App Installer  |"
Write-Host -ForegroundColor White "----------------------------------"
Write-Host -ForegroundColor White "- "

#Global vars
$AppPackageName = "";

#Loads powershell settings
Write-Host -ForegroundColor White "- Load Powershell context.."
$0 = $myInvocation.MyCommand.Definition
$dp0 = [System.IO.Path]::GetDirectoryName($0)

#Loads the SharePoint snapin
Write-Host -ForegroundColor White "- Load SharePoint context.."
$ver = $host | select version
if ($ver.Version.Major -gt 1) {$host.Runspace.ThreadOptions = "ReuseThread"} 
if ((Get-PSSnapin "Microsoft.SharePoint.PowerShell" -ErrorAction SilentlyContinue) -eq $null) {
    Add-PSSnapin "Microsoft.SharePoint.PowerShell";
[void][System.Reflection.Assembly]::Load("Microsoft.SharePoint, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9429c") 

#Imports the App package
Write-Host -ForegroundColor White "- Import app package '$AppPackageName'..."
$appPath = $dp0 + "\" + $AppPackageName;
if ($Source.Equals("ObjectModel", [System.StringComparison]::InvariantCultureIgnoreCase)) {
	$sourceApp = ([microsoft.sharepoint.administration.spappsource]::ObjectModel);
elseif ($Source.Equals("Marketplace", [System.StringComparison]::InvariantCultureIgnoreCase)) {
	$sourceApp = ([microsoft.sharepoint.administration.spappsource]::Marketplace);
elseif ($Source.Equals("CorporateCatalog", [System.StringComparison]::InvariantCultureIgnoreCase)) {
	$sourceApp = ([microsoft.sharepoint.administration.spappsource]::CorporateCatalog);
elseif ($Source.Equals("DeveloperSite", [System.StringComparison]::InvariantCultureIgnoreCase)) {
	$sourceApp = ([microsoft.sharepoint.administration.spappsource]::DeveloperSite);
elseif ($Source.Equals("RemoteObjectModel", [System.StringComparison]::InvariantCultureIgnoreCase)) {
	$sourceApp = ([microsoft.sharepoint.administration.spappsource]::RemoteObjectModel);

$spapp = Import-SPAppPackage -Path "$appPath" -Site $Web -Source $sourceApp -Confirm:$false -ErrorAction SilentlyContinue -ErrorVariable err;
if ($err -or ($spapp -eq $null)) 
	Write-Host -ForegroundColor Yellow "- An error occured during app import !"
	throw $err;
Write-Host -ForegroundColor White "- Package imported with success."

#Installs the App
Write-Host -ForegroundColor White "- Install the APP in web site..."
$app = Install-SPApp -Web $Web -Identity $spapp -Confirm:$false -ErrorAction SilentlyContinue -ErrorVariable err;
if ($err -or ($app -eq $null)) {
	Write-Host -ForegroundColor Yellow "- An error occured during app installation !"
	throw $err;
$AppName = $app.Title;
Write-Host -ForegroundColor White "- App '$AppName' registered, please wait during installation..."
$appInstance = Get-SPAppInstance -Web $Web | where-object {$_.Title -eq $AppName};
$counter = 1;
$maximum = 150;
$sleeptime = 2;
Write-Host -ForegroundColor White "- Please wait..." -NoNewline;
while (($appInstance.Status -eq ([Microsoft.SharePoint.Administration.SPAppInstanceStatus]::Installing)) -and ($counter -lt $maximum))
	Write-Host -ForegroundColor White "." -NoNewline;
	sleep $sleeptime;
	$appInstance = Get-SPAppInstance -Web $Web | where-object {$_.Title -eq $AppName}	
Write-Host -ForegroundColor White ".";

if ($appInstance.Status -eq [Microsoft.SharePoint.Administration.SPAppInstanceStatus]::Installed) {
	Write-Host -ForegroundColor White "- The App was successfully installed.";
	$appUrl = $appInstance.AppWebFullUrl;
	Write-Host -ForegroundColor White "- The App is now available at '$appUrl'.";
	Write-Host -ForegroundColor White  "- (Don't forget to add app host name in your host file if necessary...).";
	Write-Host -ForegroundColor White "- "
else {
	Write-Host -ForegroundColor Yellow "- An unknown error has occured during app installation. Read SharePoint log for more information.";


@mattengel1- I hope this helps you out if you haven't already resolved your install issue.


Derek Nishino

Nishino Consulting


I've had the same issue, it turned out to be a problem with displaying Appinv.aspx page in an iframe. It can be fixed by installing SharePoint updates or with powershell:


To display the Appinv.aspx page in an iframe in trusted domains, the farm administrator can add the trusted domains to the AllowIframeAppAuthorizePageDomains list in the farm by running the following commands:

add-pssnapin *
$f.AddGenericAllowedListValue("AllowIframeAppAuthorizePageDomains","<enable domain name>")



@msznwska This was indeed the right answer!! After running the following the issue is now resolved:


add-pssnapin *
$f.AddGenericAllowedListValue("AllowIframeAppAuthorizePageDomains","<enable domain name>")