What to do if you receive the following error “XML Parsing Error at 1:1. Error 4: Not well-formed (invalid token)” when installing a Joomla! module.
Explanation: The files in the module have been zipped using an Apple MAC. The MAC adds an extra folder called __MACOSX into the modules zip file.
Follow these steps in order to solve the problem.
Unzip (Extract) the modules zip file.
Open the unzipped (extracted) folder.
Delete the __MACOSX folder within the unzipped (extracted) folder.
Zip the unzipped (extracted) folder (The extracted module) and re-install the module and the error message will disappear.
NOTE: The module will still be installed successfully whether the error messageappears or not.