On Windows 11 24H2 with KB5055523 applied (OS Build 26100.3775), Notes 12.0.x fails to start and displays the following error message:
“Cannot complete the operation, Notes is running but not responding. Please close and restart Notes.”
HCL support recommends not to install the Windows update KB5055523 until the HCL software team fixes the issue
Workaround:
Suggestion is to run HCL Notes in compatibility Mode. If you still having the same behavior, we recommend uninstalling update KB5055523 from Windows 11.
How to run HCL Notes in in compatibility Mode?
To run HCL Notes in compatibility mode, right-click the HCL Notes shortcut or executable, select “Properties”, go to the “Compatibility” tab, and check the box “Run this program in compatibility mode for:” then choose the appropriate operating system version.
You can also adjust other compatibility settings like “Run this program as an administrator” or “Disable display scaling on high DPI settings” on the Compatibility tab.
Source: HCL KB