Font corruption Windows update KB3013455

Recently Microsoft released a critical security update causing font corruption and blurry text displayed in Notepad++. I always use Notepad++ for editing files which runs on our Windows 2008 Standard RDS Server. Last Saturday everything was just fine with Notepad++. Today I discovered that the files’s text I usually edit in my Notepad++ looked blurry. Because yesterday there were no problems I already suspected that Windows Update was causing the problem. Editing files in Windows Notepad the texts looks fine. So in my case only Notepad++ was affected. Here’s a pic showing blurry text in Notepad++.

Font corruption blurry text Windows KB3013455

Font corruption Windows – uninstall KB3013455

Looking at the Windows Update history in Control Panel I noticed last night ten updates were installed on our Windows 2008 RDS Server. To identify what update causes the Notepad++ font corruption and made the text look blurry I made a selection out of the ten recently installed updates. The first update I thought it might could cause text related problems was KB3029944. Looking at the detailed information about KB3029944 at I quote:

Vulnerability in Microsoft graphics component could allow information disclosure: February 10, 2015

The words Microsoft graphics component made me think that this update might be causing the text look so blurry. So after uninstalling KB3029944 and rebooting the Server I got disappointed finding out the text still looked blurry in Notepad++. KB3029944 was not causing problems.

The next security update that was striking my mind was KB3013455. Looking at the MS security bulletin MS15-010 – I quote:

validates data returned from user mode functions before being executed, handles TrueType Font error checking, and checks font widths prior to loading fonts into memory.

The words TrueType Font error checking made me think this has to be the one causing all the troubles. So again I went to Control Panel – Windows Update – View update history and selected Installed Updates to remove an update.

Installed updates

After removing update KB3013455 I had to reboot the Server again. As soon as the Server came up I opened Notepad++ to see if there were any changes. I was relieved to find out the font corruption problem was gone. No more blurry text in Notepad++. Problem solved! My Notepad++ files are looking normal again:

KB3013455 uninstalled

Now in order to prevent the font corruption to appear again I had to hide update KB3013455. So I went back to Control Panel – Windows Update and pressed Check for Updates. After this I pointed my mouse to KB3013455 and hit the right mouse button in order to select Hide update.

hide update

Note that this is only a temporary solution to fix the blurry text font corruption issue in Notepad++. KB3013455 is an important security update and needs to be installed on your system in order to prevent security issue’s. I will monitor this issue and wait till next security patch day and see if MS releases a new update.

If you also experience problems after update KB3013455 please share your story.


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  1. Alex schrijft:

    I have same problem.
    But I can’t remove the update – it is not in “Installed Updates” list (I can see it in update history)

    Are you know other way to remove it?

    • Marcel van der Graaf schrijft:

      have you waited till all update’s are loaded in the list? On top of the collumn you can sort by date. It should be listed there otherwise it isn’t installed.

  2. Frank Conijn schrijft:

    Thanks for this blog! 🙂 I had the same issue, which I first noticed in Firefox, on Google search result pages. And indeed in Notepad++. But with your instruction, the problem is solved. I could have waited for a patch patch by MS, but seemingly that is not so easy to make. The problem-causing patch is a week old already. I’ll keep track of this blog for further developments. Thanks again.

  3. Gavin schrijft:

    Thanks Mate, this saved me so much time. Customers everywhere complaining of blurry text.

    Maybe Microsoft needs to do more testing before release updates?

    Cheers again!

  4. Melle schrijft:

    For me the same problem in Firefox! I noticed that Explorer doesn’t have this problem! What to do about this? It’s an important security update!


  5. Frank Conijn schrijft:

    @Marcel: do you have any idea of what the actual risks are of not re-installing the update in question? I’m asking because MS would have an argument to not create/release a patch patch — the font corruption problem does not occur in IE (see Melle’s post). Personally I’m not worried at all at this moment, but that may not always stay that way.

    • Marcel van der Graaf schrijft:

      Not applying the update means your computer may be at risk. Guess we have to wait till MS releases a new update or other vendors like Notepad++ or Firefox release a fix.

  6. Joshua Rey schrijft:

    Thanks so much for this – I’d figured out how to uninstall the update, but not how to stop my computer RE-installing it, which was driving me crazy … really helpful – heel erg bedankt

  7. Roger schrijft:

    I had this same problem on my 64-bit Vista system. Microsoft knows about it and has issued a fix.
    This is from their support site, for the KB3013455 update:

    “Known issues with this security update

    – After you install security update 3013455, you may notice some decrease in text quality in certain scenarios. The problem occurs only on systems that are running one of the following operating systems:
    Windows Vista SP2
    Windows Server 2008 SP2
    Windows Server 2003 SP2
    – To resolve this issue, install update 3037639. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
    3037639 Fix for text quality degradation after security update 3013455 (MS15-010) is installed ”

    Here is the direct link to the fix:

    This fixed the problem on my system.

  8. Vicky schrijft:

    Thank you soooo much

    Hadn’t been able to resolve this at all and it was soooo annoying especially as I needed to do lots of coding!

    Have uninstalled update and just waiting for it to come up in check for updates so I can hide it.


  9. Martin schrijft:

    I’ve got the same problems, but not with Notepad++, but with IE and FF on a Windows Server 2003.
    Deinstalling the patch and rebooting the server fixes this for me at the moment.


  10. Roz schrijft:

    I had same problem, uninstalled update fixed it, but worried about security issues this may cause. Thanks for showing how to stop it re-installing itself.

  11. Lennard schrijft:

    Thanks for this! We had the same issue and deleting the update solved this problem.