Hey Stephane,
I'm really sorry about that. There is a typo in the plugin on that line that somehow got into the file and it causes this error.
We've updated the package and corrected the error. You can download the new version here:
compojoom.com/downloads/official-releases-stable/cmc/cmc-1-3-1
Now I guess that you have this error all over the place so navigating to the backend to install this new version is currently not an option. Here is what you need to do.
Login into the database, go to the #__extensions table and then search for the ecom360 redshop plugin. Edit the entry and set the enabled field to 0. This will disable the plugin and joomla won't execute it when the page loads. So your site should load after you set the enabled field to 0. Once you have this. Just navigate to the backend -> extension manager and install the new version of the extension. The installation will update the necessary files and you can enable the redshop plugin again.
Again sorry for the troubles!
Kind regards,
Daniel