There is a release note regarding a problem like this. See if this help you solve the problem:
• WebLM 8 client - The new WebLM client, which solves the https connection problem with JBoss/Wildfly, requires a manual step to make it work. Particularly it requires the trustedcert.properties file in a specific sub directory inside the app server deployment directory. The directory is different for different app server type. For Tomcat, you have to copy the trustedcert.properties from the lib directory into the webapps/WebLM/admin directory. Otherwise, you would see an exception such as the following in the console log when configuring the https license url in runtimeconfig or running the app for the first time. For other app server, take note of the similar FileNotFoundException in the console log and move the trustedcert.properties to the sub directory indicated in the exception.