diff --git a/src/Umbraco.Core/Packaging/InstallationSummary.cs b/src/Umbraco.Core/Packaging/InstallationSummary.cs
index 22818f352c..2aa74474d1 100644
--- a/src/Umbraco.Core/Packaging/InstallationSummary.cs
+++ b/src/Umbraco.Core/Packaging/InstallationSummary.cs
@@ -39,8 +39,8 @@ namespace Umbraco.Cms.Core.Packaging
 
             void WriteConflicts<T>(IEnumerable<T> source, Func<T, string> selector, string message, bool appendLine = true)
             {
-                var result = source.Select(selector).ToList();
-                if (result.Count > 0)
+                var result = source?.Select(selector).ToList();
+                if (result?.Count > 0)
                 {
                     sb.Append(message);
                     sb.Append(string.Join(", ", result));
@@ -55,7 +55,7 @@ namespace Umbraco.Cms.Core.Packaging
             void WriteCount<T>(string message, IEnumerable<T> source, bool appendLine = true)
             {
                 sb.Append(message);
-                sb.Append(source.Count());
+                sb.Append(source?.Count() ?? 0);
 
                 if (appendLine)
                 {
@@ -63,9 +63,9 @@ namespace Umbraco.Cms.Core.Packaging
                 }
             }
 
-            WriteConflicts(Warnings.ConflictingMacros, x => x.Alias, "Conflicting macros found, they will be overwritten: ");
-            WriteConflicts(Warnings.ConflictingTemplates, x => x.Alias, "Conflicting templates found, they will be overwritten: ");
-            WriteConflicts(Warnings.ConflictingStylesheets, x => x.Alias, "Conflicting stylesheets found, they will be overwritten: ");
+            WriteConflicts(Warnings?.ConflictingMacros, x => x.Alias, "Conflicting macros found, they will be overwritten: ");
+            WriteConflicts(Warnings?.ConflictingTemplates, x => x.Alias, "Conflicting templates found, they will be overwritten: ");
+            WriteConflicts(Warnings?.ConflictingStylesheets, x => x.Alias, "Conflicting stylesheets found, they will be overwritten: ");
             WriteCount("Data types installed: ", DataTypesInstalled);
             WriteCount("Languages installed: ", LanguagesInstalled);
             WriteCount("Dictionary items installed: ", DictionaryItemsInstalled);