Hello,
Since version 1.9, every time I want to update a module, I have this error message.
I can not find a solution to solve it.
Can you help me ?
Thanks in advance
Nicolas
Hi @nicolas95
Try to run compilation before what you are doing.
Make sure you take backup of your website before your run compilation.
you have to debug it this way
http://stackoverflow.com/questions/18670685/magento-error-while-installing-extension