This error means the login screen process stopped working because of problems with memory or instructions during startup. The most common cause is a damaged display (graphics) driver. Other possible causes are hard drive problems, damaged system files, viruses, or failed Windows updates. Our guide below will help you address both possible causes, along with other potential reasons for this error.
1. Run DISM Repair
Sometimes, this error appears because the LogonUI program is damaged. We’re going to walk you through using a Windows repair tool called DISM. To use it, you’ll need to boot into Safe Mode with Command Prompt. Windows will check and repair any system files that are corrupted. Once this process finishes, see if the issue is resolved. If you still have the error, you might need to repair your system files using Windows installation media. To do this, create an installation media by following Method 5 in our guide here. Once you get to Advanced Options, select Safe Mode with Command Prompt. Now your PC will boot into safe mode with a command prompt window. First, find the drive letter of your installation media by typing: D: and pressing Enter. If you see folders like boot, efi, sources, you’ve found it. If not, try E:, F:, etc. and note the correct drive letter. For this example, let’s assume it’s D:. Next, type: (Replace D: with the letter for your installation media, if needed.) Once the process is complete, restart your computer. The problem should be fixed. If not, move on to the next solution.
2. Uninstall FastAccess or Other Security Programs
Some facial recognition programs, like FastAccess, or other security software, can sometimes conflict with Windows and cause this error. If the LogonUI error appears even in Safe Mode (making you unable to log in), follow the instructions from Solution 1 to access Command Prompt. Then:
3. Disable Graphics Card Adapter
A temporary issue with your graphics adapter can also cause LogonUI to fail. To fix this, disable the graphics adapter in Safe Mode, then update and enable it in normal mode.
