Symptom: During the Magento Connect Upgrade you receive errors indicating that the new version or upgrade of mage conflicts with the existing installation:
Using SSH, go to the root directory of your Magento Install, change directory to “pkginfo” and remove “All_Mage_Latest.txt”.
Once removed, return to Magento Connect and refresh, proceed with the installation again and the error should be gone.
Symptoms: When you attempt to browse to your Magento installation or Magento directory you receive a 403 Forbidden Error.
Solution: This is a normal web server response when the requesting user does not have the rights to access the content it is trying to access. To resolve this issue check the following information:
1. Check the owner of the folder for /httpdocs/ and all subdirectories for the magento installation. The correct owner should be as follows: username:usergroup
In a Plesk 11.5 hosted environment this would be: yourusername:psaserv
If the user is root (which often happens with command line installation) change the owner of the files in httpdocs or the subfolder with the magento installation using SSH and type: chown -R yourusername:psaserv httpdocs/*
Problem: Magento Shopping cart displays blank page when items are clearly in the cart. Server Error log will display the following message: Call to undefined function mcrypt_module_open()
Solution: PHP mcrypt() Module is not installed, install mcrypt to resolve this issue.
To install mCrypt for PHP5 on your Ubuntu Linux system:
sudo apt-get install php5-mcrypt
Then restart Apache with:
sudo /etc/init.d/apache2 restart
Additionally, this problem can present itself in the admin panel as blank pages that don’t resolve, and it also throws a function error on every login.
Symptom: Magento reports that it is in maintenance mode. This often occurs after system updates. “Service Temporarily Unavailable The server is temporarily unable to service your request”
Solution: Login to the FTP and brows to the main web directory for your Magento installation, locate maintenance.flag and remove the file. The site should be live again.
Symptom: When logging into Magento Connect Manager you receive, “Invalid Login Credentials” when using the right information.
Solution: Your FTP Password was recently changed. Go to /downloader/connect.cfg and delete the file, it will automatically be recreated when you try to access the downloader again.