FIX for problems with the Windows 10 May update (1903/18362)

  • f.lux team

    Problems with the Windows 10 May update (1903) are related to "Fast Startup"

    Here is what we know:

    • If you shutdown/startup (with fast startup enabled) Windows color will fail - color profiles will not load, and f.lux will use its "fallback mode"
    • A simple reboot makes things work again (one report says logout/login is enough)
    • Starting up with "fast startup" disabled works also

    f.lux is automatically working around this bug, however screenshots will be tinted, and some dimming features and fullscreen effects will not work.

    If you typically shutdown and restart your computer and won't remember to do the extra reboot, you can disable Fast Startup using these steps:

    1. Go to Power and Sleep settings
    2. Choose "Additional power settings" to get to the old Power Options control panel
    3. From the Power Options control panel, choose "Change what the power button does"
    4. You should now be in "Power Options > System settings"
    5. Click "Change settings that are currently unavailable"
    6. Uncheck "Turn on fast startup"
    7. Restart


  • After trying these steps, I'm still unable to properly use f.lux. I'm attaching pictures. You can see there's no tinted screenshot even with f.lux "active".

    f.lux v4.105

    1_1560379729411_Untitled.png 0_1560379729411_2.png

  • f.lux team

    Are you running in HDR mode or using a 10-bit monitor?

  • @herf No, standard dynamic range 8-bit monitor.

  • Seems like the Disabling Fast Startup fixed it for me.

  • still, have this problem...

  • Just sign out user and sign in, no need to restart

  • @hallow I tried with no luck. Do you guys think it may have something to do with AMD Drives?

  • I can't use the "disable for fullscreen apps" since the may update.

    NVIDIA NVIDIA GeForce GTX 1070 (20190522)

    PnP-Monitor (Standard), 528 x 297mm, built 2017
    R=0.653320 0.334961
    G=0.323242 0.611328
    B=0.153320 0.061523
    W=0.313477 0.329102

    sRGB gamut: 93%, AdobeRGB gamut: 65%

    PnP-Monitor (Standard), 510 x 287mm, built 2013
    R=0.660156 0.330078
    G=0.294922 0.615234
    B=0.139648 0.049805
    W=0.313477 0.329102

    sRGB gamut: 100%, AdobeRGB gamut: 71%

    Windows Build: 18362.175

  • What I have figured, using @hallow's tip is that if I turn on the monitor after logging in, flux starts working.
    It works either when turning on the computer and when I sign out and then sign back in with the monitor turned off.

  • I've tried both disabling Fast Startup and rebooting after starting my laptop, and in neither case will it disable for certain apps. I can manually disable it for an hour and that's it.