Merge from 5.x: PR #20324

Fixes #20296

Author: ccordoba12

spyder/plugins/ipythonconsole/widgets/shell.py

@@ -401,7 +401,7 @@ def interrupt_kernel(self):
             # Check if there is a kernel that can be interrupted before trying
             # to do it.
             # Fixes spyder-ide/spyder#20212
-            if self.kernel_manager.has_kernel:
+            if self.kernel_manager and self.kernel_manager.has_kernel:
                 self.call_kernel(interrupt=True).raise_interrupt_signal()
             else:
                 self._append_html(