Hi, This is Wizcore/CADian. 

It has come to our attention 

that a number of errors have been reported after Windows 11 update. 

We would like to explain the causes and solutions 

for CADian being unresponsive or slow in launch 

after Windows 11 security update around Jan 20, 2026. 

Issue 1: CADian does not launch, or Error Status: 0xc0e90002

< Solution >

1. Run "Smart App Control" 

2. Set Smart App Control to “Off”.

Issue 2: Sudden slowdown or lagging behavior

< Cause >

If your CADian is suddenly too slow, unusable, or lags in launch after around Jan 20, 2026,
this should be considered an issue caused by Windows 11 Update,
rather than CADian itself. 

Windows 10 updates have now ended,
and Windows 11 users are now experiencing various errors with frequent Microsoft updates. 

In particular,
conflicts between Windows update and Graphic Card Drivers have been reported repeatedly,
and is responsible for sudden issues with CADian. 

Some of the updates that we have found to cause conflicts include 
KB5079473, KB5077181 and KB5074109.

For more details on update KB5074109, please refer to the article below:

Windows Latest : Windows 11 KB5074109 issues: black screen, freezes Outlook POP, breaks Azure Virtual Desktop, LocalizedResourceName (desktop.ini)

After this update,
NVIDIA/AMD Graphic Card Users have encountered various issues,
which has also caused various inconveniences in CADian usage. 

Microsoft has also identified issues with this update,
and has recommended that it be uninstalled ASAP

To learn how to roll back the update:
Windows Central : Windows 11 update KB5074109 is breaking systems — Microsoft says uninstall it ASAP. Here's how.

< Solution >

The issue can be resolved by rolling back Windows Update
and reinstalling the latest Graphic Card Drivers

1. How to uninstall Windows update (KB5074109):

Windows Central : Windows 11 update KB5074109 is breaking systems — Microsoft says uninstall it ASAP. Here's how.

2. Update Graphic Card Driver to latest Version
    (from NVIDIA, AMD, etc.)   
    or roll back to a previously stable driver.

Issue 3: mfc140u.dll error

If you encounter mfc140u.dll / MSVCP140.dll /VCRUNGTIME140.dll error,
please refer to the following post : 

CADian : How to fix mfc140u.dll Error

< Conclusion >

Currently, it seems updating to Windows 11 has more downs than ups.
We recommend that Windows 10 users continue using Windows 10.
If antivirus software is installed,
Windows 10 is still considered sufficiently secure
(Of course, it is still recommended to avoid suspicious links).

CADian 2026 includes various new Smart Tools, 
including Smart Dimension(SDM), Smart Detail Generator, Smart Tolerance and more, 
all of which have received positive feedback. 

Many new commands not available in other CAD software have also been introduced; we highly encourage you to upgrade & try out our CADian 2026

Explore the New Features of CAdian 2026 here

In addition, CADian 2026 features a significantly improved UI, 
providing a more comfortable design environment than before.

For any inquires, please contact us as partner@cadian.com 

Thank you, 

Sincerely, 

Wizcore/CADian