The relevant error is the
NoClassDefFound javafx/application/Platform bit.
JavaFX used to be included with the main Java Runtime but is now separate, so it's probably related to that.
Putting the error into a search engine returns this similar error, and confirms the above:
https://askubuntu.com/questions/1136420/java-lang-noclassdeffounderror-javafx-application-application
How are you launching quotestream? (i.e. do you have control over the java command executed?)
It might be enough to install OpenJFX and update the command as per the answer at the above link, or it might be that quotestream expects to run against Java 8, and you should install OpenJDK 8 LTE from either your distro's repo or from
AdoptOpenJDK.
It looks like Quotestream is commercial software, so you should definitely get in contact with them and make use of their support - either you're already paying for it, or you're evaluating it (and thus want to know how well they respond to issues).