I installed a custom Module from both marketplace, and installed normally through Magento Connect Manager. 'Till here all fine. When I went to configure it, it doesn't show up in the configuration panel. Also in disable modules output is missing. So my problem is, it's installed but I can't configure it in any way.
I also tried to download and upload it through FTP and got the same problem.
The extension is: https://marketplace.magento.com/sostanza-sostanza-livehelp.html
Thank you in advance,
@LiveHelp have you try by logging out from admin and after flushing cache again logged in.