JS issue with Magento 1.9.4.1 Adminhtml

Question

We recently upgraded our magento 1.8.1 install to 1.9.4.1, we also changed our php version from 5.6.4 to 7.2

However we are now getting an error when looking at the product page

Uncaught DOMExeption: Failed to execute 'appendChild' on 'Node': The new child element contains the 
parent.
    at klass.moveTabContentInDest

Coming from the Javascript for the Adminhtml module. This is quite a critical issue as it is stopping any edits from being made on the product's within the magento backend.

Does anyone know a way to fix this issue?

moveTabContentInDest : function(){
    for(var tab=0; tab<this.tabs.length; tab++){
        if($(this.destElementId) &&  !this.tabs[tab].contentMoved){
            var tabContentElement = $(this.getTabContentElementId(this.tabs[tab]));
            if(tabContentElement && tabContentElement.parentNode.id != this.destElementId){
                $(this.destElementId).appendChild(tabContentElement);
                tabContentElement.container = this;
                tabContentElement.statusBar = this.tabs[tab];
                tabContentElement.tabObject  = this.tabs[tab];
                this.tabs[tab].container = this;
                this.tabs[tab].show = function(){
                    this.container.showTabContent(this);
                };
                if(varienGlobalEvents){
                    varienGlobalEvents.fireEvent('moveTab', {tab:this.tabs[tab]});
                }
            }
        }
    }
    if (this.displayFirst) {
        this.showTabContent($(this.displayFirst));
        this.displayFirst = null;
    }
},

Answer 1

It's hard to see exactly what's going on without the full context, for example what is destElementId?

But generally that error sounds like you are trying to append a parent to the child block and doing so would also move the child block into itself which would be an incredibly strange thing to try and do.

If $(this.destElementId) is actually the child then it suggests the elements are the wrong way round, what happens if you change:

$(this.destElementId).appendChild(tabContentElement);

to

tabContentElement.appendChild($(this.destElementId));