As summary of the issue says, translating objects that have ezuser datatype is not possible.

Due to ezuser datatype being untranslatable, it is being displayed using attribute_view_gui instead of attribute_edit_gui. Because of that, while validating input after publishing or storing the draft of the new translation, the following block returns false due to missing POST parameters and validation fails:

kernel/classes/datatypes/ezuser/ezusertype.php, line 73:

{{ if ( $http->hasPostVariable( $base . "data_user_login" . $contentObjectAttribute->attribute( "id" ) ) &&
$http->hasPostVariable( $base . "data_user_login" . $contentObjectAttribute->attribute( "id" ) ) &&
$http->hasPostVariable( $base . "data_user_email" . $contentObjectAttribute->attribute( "id" ) ) &&
$http->hasPostVariable( $base . "data_user_password" . $contentObjectAttribute->attribute( "id" ) ) &&
$http->hasPostVariable( $base . "data_user_password_confirm" . $contentObjectAttribute->attribute( "id" ) ) )}}

Steps to reproduce

1. create an object of any class that has ezuser datatype (default user class for example)
2. translate it to another language
3. publish it
4. validation error pops up "Required data is either missing or is invalid: User account: Input required."