How to fix Internal Server Error on Joomla Sites which are not installed in the web hosting root.

Published in Joomla
One easy solution for Joomla 3.x "Error 500 - Internal server error An internal server error has occurred!"
How to fix an Internal Server Error on Joomla Sites which are not installed in the web hosting root.
Ok. So you just change your Joomla 3.x site to search engine friendly URLS, changed to mod rewrite and also renamed the htaccess.txt to .htaccess but every article page returns the error “Error 500 - Internal server error An internal server error has occured!” is that the problem? Ok here is a solution:
First remember this is just one possible solution. It won’t work for everybody. It depends on what is going wrong with your site.
It should work if this is your problem:  Joomla is installed in a folder that is not the root folder of your hosting service. When you turn Joomla SEF (in Global configuration: Search Engine Friendly URLs = YES and  Use Apache mod_rewrite = YES) the site breaks and starts showing Error 500 - Internal server error An internal server error has occurred!
The important part there is that in this case, it happens when Joomla is NOT installed in the root directory. So to fix this we have to tell the server to consider the folder where it IS located to be the root folder for Joomla. We do this by editing the .htaccess and looking for the following line:
# RewriteBase /
and we change it to:
RewriteBase /
This (effectively) tells the server to consider the root folder for Joomla is the folder that it (.htaccess) is in.
If the problem was caused by the location of your Joomla install, this SHOULD work. If it doesn’t work, it is likely that the Internal Server Error is caused by something else, that is to say the Error 500 was due to a different problem.
To help better understand the problem try this:
  • Check with a different browser, if you change something and the page has not completely refresh you might get this error
  • Refresh the page (cmd+r on Mac or F5 on windows). Sometimes you just have to wait a while or force the browser to get the latest version to fix this error. If that is the case it means other visitors to the site probably haven’t seen this error.
  • Clear you browser cache or your browser history and then reload the page
  • Clear your Joomla cache (login to the Administrator backend and click system>clear cache)
  • Turn off Joomla Caching (login to the Administrator backend and click system>global configuration in the System tab you will find cache settings, turn them off)
  • Clear your template cache. Some Joomla templates have cache login to the Administrator backend and click Extension>Template Manager - look for caching option and turn of ALL compression options (CSS/GZIP)
  • Turn off your hosting caching. You web host may have a setting for caching your content. Ask them to help you turn it off.
If you have turned off all types of caching and refreshed your browser and tried in other browser and yet the problem still persists then you can be sure it is a configuration problem, i.e. it has something to do with the settings of Joomla.
I can’t tell you what to try after that because there are a large number of things that could caus the Error 500 - Internal server error. The answer will no doubt be to do with fixing how your .htaccess is managing the redirects. I recommend going to the Joomla forum and telling them as much as you can so they can help fix the problem.
Internal Server Error
Here is the full text of the error:  “Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.”