On Linux systems, you need to install the library libidn.so.11 matching the kit you are using before installing Dollar Universe 6.
You can do so via yum installing one of these packages:
libidn-1.28-4.el7.i686 : Internationalized Domain Name support library
In order to install the latest version of the package, launch as root the following:
yum install libidn.i686
yum install libidn.x86_64
After installing this package successfully, please retry the installation/upgrade of Dollar Universe 6.