How do I debug HTTP Error 500 messages when the error_log produces no new entries?

Question

I have a website on a live server which works fine. I have just replaced the old website on the live server with a new website on the live server which is giving me a HTTP Error 500 (Internal Server Error) messages in the web browser.

The new website works fine on the dev server.

I've checked the error_log file and it is not producing error entries to match the date/time I am getting the HTTP Error 500 messages.

How do I figure out why this is not working?

UPDATE:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
#RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

If it's a PHP error : http://stackoverflow.com/questions/2687730/how-can-i-make-php-display-the-error-instead-of-giving-me-500-internal-server-er (obviously you won't know until you look) — Martin, Sep 11 '16 at 11:41
Other likely candidates are `.htaccess` screw ups. try removing/commenting out htaccess rules. — Martin, Sep 11 '16 at 11:43
@Martin, I'd hope so, the old website was using the rewrite engine without any issues whatsoever. — oshirowanen, Sep 11 '16 at 11:57
@Martin I appologies, I copied and pasted wrong. The final bracket was already in the `.htaccess` file. Corrected above. — oshirowanen, Sep 11 '16 at 12:01
You have two rewriteRules when you only should have one. And the first one appears not to do anything? — Martin, Sep 11 '16 at 12:07
@Martin, I've removed the first rewrite and still have the error message. However, I have turned on debugging in php.ini and it's now giving me a more details error message. I guess this question is no longer relevant. Thanks for the help. I'll try closing. — oshirowanen, Sep 11 '16 at 12:24
Glad you got a lead on sorting it. don't close it, but not sure if as an author you are still able to mark it as a duplicate? — Martin, Sep 11 '16 at 12:32
@Maybe someone can tell me to turn php debugging on in php.ini? and I could accept? :D But that's probably cheating... — oshirowanen, Sep 11 '16 at 12:48
@oshirowanen https://docs.joomla.org/Edit_PHP.INI_File_for_XDebug (Accept now?) — baranskistad, Sep 11 '16 at 19:05

score 1 · Answer 1 · edited May 23 '17 at 12:15

1

An unlogged 500 error on an apache server almost certainly means there's something wrong with your .htaccess file.

Try commenting out a few lines at a time or deleting them from your .htaccess file.

Useful further information as to causes of unreported error 500s can be found here.

edited May 23 '17 at 12:15

Community

1
1

answered Sep 11 '16 at 11:44

baranskistad

2,176
1
21
42

it doesn't just mean that, but that is a likely cause. The OP was asking for how to debug this cause, rather than fix the problem. How would you go about checking it's `.htaccess` rather than an issue with an unloaded apache module, for instance? – Martin Sep 11 '16 at 11:48
@Martin From all of my past experiences with PHP, (and as a PHP dev that's a lot) it has always been the `.htaccess`. – baranskistad Sep 11 '16 at 11:50
@Martin If you know any other issue possibilities, feel free to suggest an edit, or comment it. – baranskistad Sep 11 '16 at 11:51
Oh yes, me too, but there can be other issues such as apache modules expected but not loaded, I see the question as being more *how* to debug rather than what the cause is in this specific instance. (Sorry I feel I'm being a bit anal here) – Martin Sep 11 '16 at 11:53
@Martin I see. Before we _can_ debug the error I think they need to share more about their files. – baranskistad Sep 11 '16 at 11:55

How do I debug HTTP Error 500 messages when the error_log produces no new entries?

1 Answers1