Maximum key size must be smaller 32 Magento

1.-Flush your cache if it doesnt work check PHP version it must be 5.5.
     Write in any file <?php echo 'Versión actual/Actual version  PHP: ' . phpversion(); ?>

2.-If it doesnt work check the app/etc/local.xml file an change your line instead this one

  <key><![CDATA[ec9d0046fcf435bc516ea43bab9798fa]]></key>

Unable to find writable var_dir Magento

1.-Check the permission of your folder  it must be 0777,{{MAGENTO_ROOT}}/var , if it doesnt exist you must create it.

How to change permissions in Linux

REFRESH,IF IT DOESNT WORK CONTINUE TO STEP TWO

2.-Go to the {{MAGENTO_ROOT}}/app/code/core/Mage/Core/Config/Options.php

Replace this function for this one,if you are a good observer you can see that is the same code but the second line is commented.


 public function getVarDir()
    {
        $dir = $this->getDataSetDefault('var_dir', $this->getBaseDir().DS.'var');
       // $dir = isset($this->_data['var_dir']) ? $this->_data['var_dir']: $this->_data['base_dir'] . DS . self::VAR_DIRECTORY;
        if (!$this->createDirIfNotExists($dir)) {
            $dir = $this->getSysTmpDir().DS.'magento'.DS.'var';
            if (!$this->createDirIfNotExists($dir)) {
                throw new Mage_Core_Exception('Unable to find writable var_dir .2.');
            }
        }
        return $dir;
    }

3.-Try again.

How to add input text attribute on order by bar Magento

Sadly you cant do this but I have found a solution.The solution consist converting your input text in to a select field.

1.-Create a new input select field.
2.-Copy and paste this code in a new php file.Download here
3.-Edit the first variables with your own attributes to change and save the file as changeattr.php .
4.-Open the terminal and get over the root magento's folder.
Example on windows
cd c:/xampp/htdocs/magento

Example on linux

cd /var/www/magento

4.-Once you are on the folder type in the terminal   php changeattr.php  .
5.-The file is going to save all the values used in a .cvs in order to export to the new attribute,and the script is in charged of all the hard work.