Error: 0 Call to undefined method JAdminCssMenu::addChild()

After installing the mod_data_admin_menu module, only the top toolbar is displayed. Viewing the pages source code, "Error: 0 Call to undefined method JAdminCssMenu::addChild()" is shown as the issue.

I believe this is due to the fact that there is a conflict between com_menu and mod_data_admin_menu. the both have the same JAdminCssMenu class name.

To resolve this issue, I renamed the JAdminCssMenu class in mod_data_admin_menu to JVdataAdminCssMenu. I also change reference to JAdminCssMenu in the mod_vdata_admin_menu.php file to use the new class name.

Maybe use namespaces in the future?

Thanks, Scott

Hello,
Thanks for reporting it to us, will resolve it ASAP.

I have the same issue, cant find the file you talk about, please help!! We have a News Agency that has no BACKEND ACCCESS NOW!!!!

Hello,
The issue is resolved, vData 2.9.13 has got the fix.

I already restored the site to an earlier version, uninstalled your program and upgraded Joomla to 3.8 - problem solved.

That's alright, but if you can still use it if you have any further task on Joomla 3.8 website. The latest version is working perfectly fine now.