Redhat 8 does not include a library needed by the UnForm 9 or 10 runtime. This library can be installed like this:
sudo yum install libnsl
Also, to install ImageMagick, the EPEL library needs to be enabled first:
sudo yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
sudo yum install ImageMagick
If you need SSL support, you should also install an openssl compatibility layer:
sudo yum install compat-openssl10
The UnForm 10 ufsetup.sh program performs these steps for you, but version 9 requires manual steps.