"We have seen the errors of our ways and are releasing a new installer (and a new version of the software) later today. The new installer will find all valid "Claris Emailer Files" folders and install the 2.0 necessary files in there. It will no longer move the Emailer 1.1 application to the trash. This will address 95% of the problems that people were having.
The conversion has never made it so that you could not go back to 1.X. It has always created a folder called "Emailer 1.X Backup" where it would copy all files that were changed by 2.0 in a way that they were incompatible with 1.X. To go back to 1.X you could copy these files out of the backup folder. All of this was explained in the installation instructions."