Fatal Error after upgrade

After my upgrade a few things happened

1. The home page on the cart went to some info about zencart. All of the contact info etc, went away.
2. I get Fatal error: Cannot redeclare date_diff() in /home/heartlan/public_html/store/admin/includes/functions/general.php when trying to log in.

Any ideas?

Thanks.

Carl

1. "went to some info about zencart".
   It would be much more helpful to know WHAT it says, instead of something vague.

2. "Cannot redeclare date_diff()"
   That means you've got multiple files on your site that are declaring the date_diff() function, and they're clashing.
   One common cause of that sort of thing is renaming a file (thinking you're making a backup) from something like "functions_something.php" to "functions_something_bak.php" but because you've left the ".php" on the end you're telling ZC that it's okay to load that ".php" file. And because it contains much of the same content as the original file, you're getting duplicate function declarations.
   Similarly related, if you had v1.3.8 and added a patch to support PHP 5.3, and then upgraded to 1.3.9 or 1.5.0 but didn't remove the patch files from the older versions, then you might trigger similar problems.

I did upgrade from 1.3.8 to 1.3.9 because of the php.

Do you know what files I should remove?

Also this is what I am seeing on the home page

Congratulations! You have successfully installed your Zen Cart™ E-Commerce Solution.
Welcome Guest! Would you like to log yourself in?

https://www.heartlandharvest.com

Thanks.

Any update on what files I would need to remove would be great.

http://www.zen-cart.com/showthread.php?182712-PHP-ver-5-3-PHP-Fatal-error-Cannot-redeclare-date_diff%28%29-in&p=1085950#post1085950

csaling:

Any update on what files I would need to remove would be great.
Specifically, any files that didn't come with Zen Cart core code need to be assessed and removed if they're not part of addons you intended to add.
So, if there are extra files leftover from the old version, then you need to remove them. That's part of a proper upgrade process, and is mentioned in the upgrade instructions.

Using tools like WinMerge make the identification of "extra" files very quick and simple: http://www.zen-cart.com/wiki/index.php/Troubleshoot_-_Diagnosing_Obscure_Issues