I upgrades to 1.9.2. and it crashed in some way during installation with connect. Since then i can't login to admin because the admin page is totaly blank (in the source of the page is totaly notting).
Also the home page (and al others) are missing CSS.
This happened to me as well after an upgrade (for an existing shop in a test environment) from 1.8 to 184.108.40.206 I couldn't find any errors in the log files or even in the apache error files. No idea what happened (and I have done several updates like this before!). Then I noted some files were missing in the skin and quite a few files were missing in the app/design/adminhtml/default/default/layout and .. template directories! No wander backend looked so empty. I downloaded a 220.127.116.11 package, unpacked it and copied all the app/design/adminhtml/default/default/.. over my existing app/design/adminhtml/default/default/.. files and did the same for the skin/adminhtml. I do not know why the files disappeared but I got my backend back and all worked fine afterwards.
So, if you find a blank (or part of) admin after an upgrade, check for errors but also check that app/design/adminhtml/ still contains all files
This was really helpful mate well done.
I did as you said "unpacked it and copied all the app/design/adminhtml/default/default/.. over my existing app/design/adminhtml/default/default/.. files and did the same for the skin/adminhtml."
It works for me Thanks
The wider issue is why this happens in the first place. If you upgraded over the command line, look back and you'll probably see that there was an error when it was trying to install the package which provides the admin panel :
Starting to download Interface_Adminhtml_Default-18.104.22.168.tgz ... ...done: 1,014,585 bytes Installing package community/Interface_Adminhtml_Default 22.214.171.124 Error
It will have carried on with the remainder of the installation, but you were left without an admin panel.
Try to install it afterwards manually and you'll probably see something like this :
-sh-4.2$ sudo ./mage install http://connect20.magentocommerce.com/community Mage_Core_Adminhtml Checking dependencies of packages Error: install: Package community/Mage_Core_Adminhtml failed: Unknown cipher in list: TLSv1
That, in turn, would lead you to this SE thread suggesting that you edit downloader/lib/Mage/HTTP/Client/Curl.php to change the line which reads :
Do that, attempt the upgrade again, and it should go through okay. If you look back through your history the chances are you'll also need to install the Interface_Frontend_Rwd_Default package as well.