Here is my setup:
System76 Gallago Pro
Fedora 30
OpenJDK 1.8.0_201 (I did try Oracle as well)
I installed per IBM's instructions, using the installer script from the command line. I went through the installer menu and got to the success screen. I have done this a half dozen times on other machines and with OS upgrades on this same machine.
When I use the super key to find the program it is there; I click on the icon and my box returns to the desktop - but i Access doesn't start.
If I start via the command line using the start script, I get MSGGEN045 - A graphical user interface is not available.
If I run the java program directly
java -Xmx1024m -jar /opt/ibm/iAccessClientSolutions/acsbundle.jar I get the same message as when using the start script.
How can I get past this error? Or,what else can I do to track down what is happening?
I don't have anything Fedora specific but it seems that you either didn't install a Java Runtime Environment or just a headless version of it (jre-headless). Install a full JRE and everything should be fine.
You could check this with yum:
yum list installed | grep jre