Exactly how did you install Vassal?
- From https://vassalengine.org from a tar-ball, or
- via FlatPak and FlatHub?
It looks like you are using a Java Runtime Environment (JRE) provided by Homebrew, and the problem seems to stem from there. Perhaps try to install the RedHat JRE as outlined in 
Redhat and derivatives.
Do you have problems with other Java applications using the Homebrew JRE?
Yours,
Christian