Upgrading Drupal

How to fix this?

Error
Error messageDatabaseSchemaObjectExistsException: Cannot add index system_list to table system: index already exists. in DatabaseSchema_mysql->addIndex() (line 437 of /home/ns/www/www/includes/database/mysql/schema.inc).
The website encountered an unexpected error. Please try again later.
Uncaught exception thrown in session handler.

I am using godaddy webhosting. I was running the update, and backed up my website on godaddy. Suddenly my page turned into maintenance mode and is going to an ERROR that says, "The website encountered an unexpected error. Please try again later."

I cannot log in to my admin using /user or anything else. PLEASE help me get my website off this maintenance mode!!!!

Hi all,

I'm having an issue with security update, in particular with Drupal Core 7.24, in order to do this I've seen that I need to make some changes on the .htaccess in some subfolders, the post with the details for the correct installation on:

• https://drupal.org/SA-CORE-2013-003

says that I need to make some changes in the .htaccess specified in the status report of drupal.

Hello.

I've got two issues:

1. I have a website based on Drupal 7.21 core (upgraded from earlier releases), but cannot not update the Views module to the last version: all old views just disappear, and that compels me to create them from the scratches and that's a real hard work with no time for it. Therefore I consider it would be better to wait for 8.x release and upgrade the whole website at once - I know, such update will take a month at least. Is my decision proper?

Upgraded to 6.29 and modified/added the prescribed file to my /files and /temp folder. however, I still get the status error saying that my /tmp folder is not secure/vulnerable. I have followed the instructions to the letter. Can I get some help/advice please?

Here is some facts:

The database update.php doesn't work anymore. Review updates says four modules need updated (backup_migrate, chatblock, media_youtube and webform) but when I click Apply pending updates there will be menu still and title Updating but otherwise white screen and nothing happens anymore. Should I wait hours or how to proceed?
When I try again the anything hasn't change and I can repeat this many times. The database size is something 4 MB.