Hi, I am getting the below error whenever I try to edit a "conversation block" I have no idea how to rectify this. I share the main concrete code between different sites so that's why the /usr/local/share.... directory. This should not be the issue because every other block, theme,addon etc work just fine. Please Help:

implode(): Invalid arguments passed
Details
/usr/local/share/concrete5/concrete5-8.5.4/concrete/blocks/core_conversation/form.php(252): Whoops\Exception\ErrorException->null
/usr/local/share/concrete5/concrete5-8.5.4/concrete/blocks/core_conversation/form.php(252): null->implode
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/Block/View/BlockView.php(361): null->include
/usr/local/share/concrete5/concrete5-8.5.4/concrete/blocks/core_conversation/edit.php(4): Concrete\Core\Block\View\BlockView->inc
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/Block/View/BlockView.php(248): null->include
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/View/AbstractView.php(164): Concrete\Core\Block\View\BlockView->renderViewContents
/usr/local/share/concrete5/concrete5-8.5.4/concrete/views/dialogs/block/edit.php(33): Concrete\Core\View\AbstractView->render
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/View/View.php(267): null->include
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/View/View.php(245): Concrete\Core\View\View->renderInnerContents
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/View/AbstractView.php(164): Concrete\Core\View\View->renderViewContents
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/Routing/ControllerRouteAction.php(82): Concrete\Core\View\AbstractView->render
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/Http/RouteDispatcher.php(37): Concrete\Core\Routing\ControllerRouteAction->execute
/usr/local/share/concrete5/concrete5-8.5.4/concrete/src/Http/Middleware/DispatcherDelegate.php(39): Concrete\Core\Http\RouteDispatcher->dispatch