From 392eec237182c4cc669d23b797d7a4762d49693e Mon Sep 17 00:00:00 2001
From: Bjarke Berg <mail@bergmania.dk>
Date: Wed, 25 Aug 2021 11:56:20 +0200
Subject: [PATCH] Fixed potential null reference exception in KeepAlive

---
 src/Umbraco.Infrastructure/HostedServices/KeepAlive.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Umbraco.Infrastructure/HostedServices/KeepAlive.cs b/src/Umbraco.Infrastructure/HostedServices/KeepAlive.cs
index 40c250f86e..644b2c278f 100644
--- a/src/Umbraco.Infrastructure/HostedServices/KeepAlive.cs
+++ b/src/Umbraco.Infrastructure/HostedServices/KeepAlive.cs
@@ -33,7 +33,7 @@ namespace Umbraco.Cms.Infrastructure.HostedServices
         /// <summary>
         /// Initializes a new instance of the <see cref="KeepAlive"/> class.
         /// </summary>
-        /// <param name="requestAccessor">Accessor for the current request.</param>
+        /// <param name="hostingEnvironment">The current hosting environment</param>
         /// <param name="mainDom">Representation of the main application domain.</param>
         /// <param name="keepAliveSettings">The configuration for keep alive settings.</param>
         /// <param name="logger">The typed logger.</param>
@@ -86,7 +86,7 @@ namespace Umbraco.Cms.Infrastructure.HostedServices
 
             using (_profilingLogger.DebugDuration<KeepAlive>("Keep alive executing", "Keep alive complete"))
             {
-                var umbracoAppUrl = _hostingEnvironment.ApplicationMainUrl.ToString();
+                var umbracoAppUrl = _hostingEnvironment.ApplicationMainUrl?.ToString();
                 if (umbracoAppUrl.IsNullOrWhiteSpace())
                 {
                     _logger.LogWarning("No umbracoApplicationUrl for service (yet), skip.");