Kotlin-android: Unresolved reference

Question

I have received this project from the previous developer, and he said everything is working fine on his end. But on my end, when I try to sync the project I get a lot of errors, and I don't know where to even start. One of them is this:

Here's that code:

private fun setupScrollDirection() {
        val allowHorizontalScroll = config.scrollHorizontally && config.viewTypeFolders == VIEW_TYPE_GRID
        excluded_vertical_fastscroller.isHorizontal = false
        excluded_vertical_fastscroller.beGoneIf(allowHorizontalScroll)

        excluded_vertical_fastscroller.allowBubbleDisplay = config.showInfoBubble
        excluded_vertical_fastscroller.setViews(manage_folders_list) {
            excluded_vertical_fastscroller.updateBubbleText(getBubbleTextItem(it))
        }
    }

I have a lot more errors of the same type, like this one for example:

Answer 1

Please have a call with the other developer and ask him/her to share his screen on call.

When the screen is being shared, ask the developer to Ctrl+ Click on beGoneIf variable/function and then check where the beGoneIf is defined in the project. This way you can check whether the required library/dependencies used by other developer is present in your local project or not.