Cannot login to backend of live site after upgrade.

[Kev261266]

I've started to upgrade my 1.7.3 sites to the latest 2.5.6 versions.
As a safety net I've been using akeeba to back the live site up which I've then installed on my local machine running XAMPP 1.7.4.

I then upgrade the site to version 2.5.6 (which upgrades fine) and hey presto the new upgraded site works fine on my localhost (both frontend and backend)

The problems start when:

1. The backend advises there is a new version of akeeba, which I download & install.
2. When I click on akeeba to make a backup of the site, I get a huge warning advising me that I have an outdated php and need to upgrade to php 5.3.
3. Akeeba still makes the back up, which I ftp across to my live server.
4. I use Akeeba Kickstart to install the backup file.
5. My site frontend works perfectly, BUT I can't log in to the backend! I get the login page, but once I insert my user and password it goes to blank page (in Firefox) and a server error "HTTP Error 500" (in Chrome)

I'm assuming it's something to do with the php and 2.5.6 Joomla, but don't know what I need to put right.

I've not changed the XAMPP version, because in the past later versions of XAMPP caused problems with Joomla.

Any idea of how I can get logged into the backend or where I'm going wrong?

Thanks.

Kev.

[humvee]

[Mod note: Moved from Installation Forum to Upgrade Forum;]

[Kev261266]

SOLVED

Okay, I fixed this and now have the sites in question running 2.5.6 on live servers and I can actually log in to the backend. I shall attempt to describe how I did this.

I still had an Akeeba backup of the 1.7.3 site which I'd taken from the live server before it all went wrong.

1. In my localhost I created a fresh database with a new name to avoid confusion
2. Created a new folder for the Joomla install.
3. copied the backup file and kickstart into the new folder, and did the akeeba magic, using the new db info.
4. I now had a 1.7.3 site on localhost, and I could log into the backend.
5. Take a backup copy of the 1.7.3 site.
6. On my live server I created a fresh database and did an akeeba install using kickstart and the new db info.

At this point the frontend of the site was working, but I COULD STILL NOT LOGIN TO THE BACKEND. (I believe this was due to the fact that I had not done a fresh Joomla install)

7. Using this address mysite/administrator/index.php?option=com_users&view=users
I managed to get into the backend of the site and went to the extension manager where I upgraded to 2.5.6.
8. I could now log out and log back in as usual.
9. To finish I upgraded Akeeba and any other stuff that showed up as needing to be upgraded in the extension manager.
10. Checked again to make sure the backend login was still working.

And it was.

This seems so convoluted that I'm not sure it will help anyone, but you never know.

Cheers.