500 internal server error

I have been utterly rigorous in regard to configure files, still have /admin named as such, and the install process seems to complete OK, but when I click on the link to go to the store, I get the following error:

'Server error
The website encountered an error while retrieving http://www.domain.com/catalog/index.php. It may be down for maintenance or configured incorrectly.
Here are some suggestions:
Reload this webpage later.
HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.'

I have actual domain name in there.

When I click on the 'go to admin' link, I get the

Hello. Thank you for loading Zen Cart®.

You are seeing this page for one or more reasons:... page.

Config files are not thrown up in red through installation.

Reading indicates a general server error. How might I proceed?

godt:

HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.'

Probably just your file or folder permissions being set too liberal for your specific server's master configuration.

FAQ on dealing with "500 internal server" errors: http://www.zen-cart.com/content.php?105-why-am-i-getting-500-internal-server-error

godt:

When I click on the 'go to admin' link, I get the

Hello. Thank you for loading Zen Cart®.

You are seeing this page for one or more reasons:... page.
It's actually kinda important to READ those reasons. Reasons 1 and 2 are typical causes. If there's a 3rd reason listed, it's more specific.

Usually means wrong paths in your configure.php files.

Just to add: if I remove the configure.php files and attempt an install with the dist-configure.php files, I do not get the option to upgrade.

godt:

Just to add: if I remove the configure.php files and attempt an install with the dist-configure.php files, I do not get the option to upgrade.
Right: because the dist-configure.php files don't contain any database settings, thus the system can't find your database, and therefore doesn't have anything to upgrade.

OK. Thanks. In the absence of any errors - that I can see - in the config files, I'll follow that up. I have config files at 777.

In regard to the dist-config files issue, that makes sense! Thanks.

Are you trying to upgrade-in-place directly on your live site? or are you using a temporary copy of your site and upgrading that temporary copy FIRST, before touching your live site?

godt:

OK. Thanks. In the absence of any errors - that I can see - in the config files, I'll follow that up. I have config files at 777.755 might be what your hosting company requires you to use on your server. That's becoming more and more common these days.

Server people can find no errors, no logs of errors. I've tried all suggested combinations of permissions for files and folders. But I have got a string of myDEBUG- files which say:

[19-Feb-2013 01:45:50 UTC] PHP Fatal error: Class 'QueryCache' not found in /home/.../public_html/catalog/includes/autoload_func.php on line 79

and a few

[18-Feb-2013 03:05:43 UTC] PHP Warning: error_log(/home/.../public_html/dev/cache/page_parse_time.log) [<a href='function.error-log'>function.error-log</a>]: failed to open stream: No such file or directory in /home/.../public_html/catalog/47868/includes/classes/logger.php on line 60

godt:

But I have got a string of myDEBUG- files
thud - exactly: http://www.zen-cart.com/content.php?124-blank-page

godt:

PHP Fatal error: Class 'QueryCache' not foundMissing file. Upload it.
godt:

PHP Warning: error_log(/home/.../public_html/dev/cache/page_parse_time.log) [function.error-log]: failed to open stream: No such file or directory in /home/.../public_html/catalog/47868/includes/classes/logger.php on line 60

/home/.../public_html/catalog/47868/includes/classes/logger.php -- note the path here tells me where your store is actually located.
But note that the log file your store is set to use points to a path that's quite different: /home/.../public_html/dev/cache/page_parse_time.log
That's common when moving from one server to another. To fix that, you'll need to login to your Admin and set the page-parse-time-log filename to the correct path and filename in the Admin->Configuration->Logging section. Or, better yet, turn off page-parse-time logging altogether.

DrByte:

Are you trying to upgrade-in-place directly on your live site? or are you using a temporary copy of your site and upgrading that temporary copy FIRST, before touching your live site?

Sorry, didn't see this: I had set up a new install of 1.5.0 in a subdirectory next to the existing live site, and am upgrading that to 1.5.1. If worse comes to worse, I guess I'll have to do a clean install of 1.5.1 and rebuild the current database.

But what is the missing file? Autoload_func is there.

Can't log in to admin. Sounds like worse has come to worse.

godt:

But what is the missing file? Autoload_func is there.
Autoload_func is only reporting the problem.

An error message of "PHP Fatal error: Class 'QueryCache' not found" means your /includes/classes/query_cache.php file is not present or couldn't be loaded. That was added in 1.5.1, so it appears you've missed uploading some files?

DrByte:

Autoload_func is only reporting the problem.

An error message of "PHP Fatal error: Class 'QueryCache' not found" means your /includes/classes/query_cache.php file is not present or couldn't be loaded. That was added in 1.5.1, so it appears you've missed uploading some files?

And that would be an understatement. A slow read through the debug files pointed to the fact that I had not uploaded any of the new files. But I did a great job of checking and merging all the changed files!

All of the above is help much appreciated. Certainly by someone who can't see the wood for the trees, or vice versa.

godt:

A slow read through the debug files pointed to the fact that I had not uploaded any of the new files. But I did a great job of checking and merging all the changed files!
Don't laugh: I've done the SAME thing! On more than one occasion :blush:

Remember also to remove any files that don't belong anymore. I think the list of those is really short if only going from 150 to 151.