Bootstrap-select: Empty dropdown when i make one

[Goten87]

i wanned to add your multi select option for my website but it is not working at all

<select class="form-control selectpicker" multiple name="extra[]" id="Extra">
    <option value="lvling">Leveling</option>
    <option value="farming">Farming</option>
    <option value="dungeon">Dungeon Friendly</option>
    <option value="raid">Raid Friendly</option>
</select>

this is my code when i go to my website and open the Select the Select dropdown is compleetly empty no data in it at all
so what am i doing wrong

i use boostrap 4
and jquery 3.2.1
also i have jquery UI installed

[MinChanSike]

I think it is because of Bootstrap version 4.
By documentation - This version currently does not support Bootstrap 4 officially.

[caseyjhol]

Bootstrap 4 support has been added as a part of v1.13.0-beta, available here: https://github.com/snapappointments/bootstrap-select/releases/tag/v1.13.0-beta.

[Goten87]

To @caseyjhol Will try that tomorrow

[Goten87]

also i use

<optgroup class="HideAll Show1">
<option class="HideAll Show1">option 1</option>
<optgroup>

but i hide them on the other selects i use but all the lines stay what can i do to fix that
so that when i hide all and show 1 it will only show that and not all the other <li> lines as well sins i have a lot of it

[caseyjhol]

Bootstrap 4 support has officially been added in v1.13.0!