diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 5c4de5c..fd97328 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -89,7 +89,7 @@ jobs:
       matrix:
         include:
           # Note: Nosetest doesn't work anymore with recent Python versions!
-          - {qt: "5", runner: "macos-12", nosetests: 0}
+          - {qt: "5", runner: "macos-13", nosetests: 0}
           - {qt: "6", runner: "macos-14", nosetests: 0}
     env:
       FUNQ_QT_MAJOR_VERSION: "${{ matrix.qt }}"
diff --git a/server/funq_server/runner_win.py b/server/funq_server/runner_win.py
index bfab975..2a96f8d 100644
--- a/server/funq_server/runner_win.py
+++ b/server/funq_server/runner_win.py
@@ -215,8 +215,13 @@ def _raise_windows_error(self, function_name, return_value):
         """
         last_error = ctypes.get_last_error()
         win_error = ctypes.WinError(last_error)
+        try:
+            # Try formatting as hex.
+            return_value = "{} (0x{:X})".format(return_value, return_value)
+        except TypeError:
+            pass
         message = "Failed to inject DLL! "
-        message += "{} returned 0x{:X}. ".format(function_name, return_value)
+        message += "{} returned {}. ".format(function_name, return_value)
         message += "The last error is 0x{:X} ({}). ".format(
             last_error, str(win_error))
         message += "Maybe x86/x64 mismatch between python.exe and Qt DLLs?"