I am tyring to upgrade my joomla to the latest version(3.6.2 to 3.6.5), but no matter I install it online or download the package and install from local, I got a 500 error. Also when I try to open components->akeeba I get a 500 error too. I host the website on my own linode server, when I check apache error log where I usually go to find the error logs, I didn't find anything. By the way, my front-end works well and there is no problem with other functions on back-end.
Where could the error log be and more importantly how to solve this upgrading problem? Without being able to see the detail of the 500 error, I am lost.