In most cases these errors are occurring because your server is using ModSecurity to block certain request from Interspire Email Marketer.
You can solve these errors by disabling ModSecurity for your domain. If you do not want to do any file editing then you can request that ModSecurity be disabled by your web hosting provider. Otherwise, you can disable ModSecurity by creating a .htaccess file in your domain's root directory. Populate the .htaccess file with this data:
SecFilterEngine Off
SecFilterScanPOST Off
