Ive followed the Tutorial for creating a custom plugin from Plural site tutorial
However as of now it is a little out of date with Nop version 3.8.
Ive followed the tutorial and made one change (the admin menu).
Im about to create the "CreateUpdatePromoSlider.cshtml" but im hit with an issue.
<li @Html.RenderSelectedTabIndex(0, GetSelectedTabIndex())>Slider</li>
Try to use
@Html.RenderBootstrapTabContent methods instead of
@Html.RenderSelectedTabIndex. They are now used in nopCommerce admin panel.