diff --git a/src/installer/managed/Microsoft.NET.HostModel/AppHost/AppHostExceptions.cs b/src/installer/managed/Microsoft.NET.HostModel/AppHost/AppHostExceptions.cs
index ceae7c46cdc80f7e4301c254c8add2e9910c48f7..fe934661af6aba5bcaf57db0d08d92cbabf62424 100644
--- a/src/installer/managed/Microsoft.NET.HostModel/AppHost/AppHostExceptions.cs
+++ b/src/installer/managed/Microsoft.NET.HostModel/AppHost/AppHostExceptions.cs
@@ -37,6 +37,7 @@ public sealed class AppHostMachOFormatException : AppHostUpdateException
         public readonly MachOFormatError Error;
 
         internal AppHostMachOFormatException(MachOFormatError error)
+            : base($"Failed to process MachO file: {error}")
         {
             Error = error;
         }
diff --git a/src/installer/managed/Microsoft.NET.HostModel/AppHost/HostWriter.cs b/src/installer/managed/Microsoft.NET.HostModel/AppHost/HostWriter.cs
index be83a7067d794cc94b3a6d11ff094e46fa0cdbb2..bbb1b421aac1baf9eb6de67959e82488bdf5bbe0 100644
--- a/src/installer/managed/Microsoft.NET.HostModel/AppHost/HostWriter.cs
+++ b/src/installer/managed/Microsoft.NET.HostModel/AppHost/HostWriter.cs
@@ -141,7 +141,7 @@ void UpdateResources()
 
                     if (chmodReturnCode == -1)
                     {
-                        throw new Win32Exception(Marshal.GetLastWin32Error(), $"Could not set file permission {filePermissionOctal} for {appHostDestinationFilePath}.");
+                        throw new Win32Exception(Marshal.GetLastWin32Error(), $"Could not set file permission {Convert.ToString(filePermissionOctal, 8)} for {appHostDestinationFilePath}.");
                     }
 
                     if (enableMacOSCodeSign && RuntimeInformation.IsOSPlatform(OSPlatform.OSX) && HostModelUtils.IsCodesignAvailable())