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Fixed in 2017.1.0f3



Found in


Issue ID




UI Dropdown list does not render if the Canvas is disabled and enabled again



To reproduce:

1. In a new project, create Canvas
2. Press Play
3. Disable Canvas
4. Enable Canvas
5. Create Dropdown
6. Click on Dropdown list in Game view

Expected: Dropdown list renders properly no matter what you do with the Canvas at runtime
Actual: Dropdown list does not render properly when you disable and enable Canvas

Reproduced in 5.6.0f1, 5.6.0f2, 5.6.0f3, 2017.1.0a6
Did not reproduce in 5.5.2p4
Regression introduced in 5.6.0f1

Comments (9)

  1. 02c025d3d3443b1ff7bfb30b52f0763f?d=mm


    Aug 03, 2020 14:27

    I found this bug on 2019.4.6 (LTS) too

  2. 4e4d6260e8d13210062352e3859f7a5a?d=mm


    Oct 23, 2018 15:27

    I solved this issue by adding a Canvas component to the "Template" object and uncheck "Override Sorting", so that the dynamically generated "Dropdown List" will appear on the correct sorting layer.

  3. 5c47876f94f10d1acc9929322a180f04?d=mm


    Oct 09, 2018 15:21

    The problem is at line 301of Dropdown script.

    Add a CanvasGroup to your Template GameObject and disable it.

  4. 5c47876f94f10d1acc9929322a180f04?d=mm


    Oct 09, 2018 14:34

    2018 2.2f1there is still.
    A canvas group is created (I imagine for the transition fade) and the alpha stays at 0.

  5. 6ae7bc4a8a8378cdb27559a28ccafce9?d=mm


    Feb 05, 2018 15:16

    I have 2017.3.0f3 and I have this (or very nearly this) issue. But I also have a workaround. Bear with me:

    a) I don't use gameobject enable/disable for my canvas - I use a canvasGroup and alter Alpha/Interactable/Blocks Raycasts. Don't remember why, probably cause the other is buggy.

    b) I have the following sorting layers: Default / BG / Dialog

    c) I have a background UI canvas that is set on the BG sorting layer, then a dialog panel with options toggles on/off above this in the dialog sorting layer. The dropDown is on the dialog panel. When I open my dialog panel and use the dropDown, it does not show the options, though I see the DropDownList's outline in the Scene view.

    d) The problem seems to be that the DropDown List is instantiated on the default sorting layer. After it is selected it is destroyed and clicking it again re-instantiates it on the default layer (which is behind both my dialog and BG layers). Hence not visible.

    e) I fixed this by simply re-arranging my sorting layers so that the default is the top, ie: BG/Dialog/Default

  6. 2569bdbc62c83ce03a14a9575310585d?d=mm


    Dec 08, 2017 09:42

    I am using 2017.1.1f1 and it is still there.

  7. 3d4120d94c5ee2a45ddd33d05f29b63a?d=mm


    Jun 24, 2017 17:20

    I'm using 2017.1 and it still there. :\

  8. 643afa85831825e3d3fd9b8bc27531a7?d=mm


    Apr 25, 2017 17:26

    i have 5.6.0f3 and it is happening..

  9. C09eda028e43c3c4000aeafbf48c72f9?d=mm


    Apr 18, 2017 15:46

    it's back again in 5.6 .

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