It is very frequent for us,  that we are going to add a new module to our Joomla, and we do not remember the positions of the modules in the template. Each template will have some positions defined for the modules that it has recognized; these positions will therefore be different from one template to another.

After an update to Joomla 3.8.10 some users are getting errors and they can not use the menu.

Screen pops up the following error message

Cannot Use Object Of Type StdClass As Array

The solution is quite simple:

Edit the file "helix3.php" (plugins/system/helix3/helix3.php)

And add the following code on 50 line:

if (is_object($data)) {

           $data = (array)$data;

}

After the line: JForm::addFormPath(JPATH PLUGINS.'...)

And before the line: if ($form->getName()=='com_menus.item')