I can't figure out why my plugin sandbox shows a different font than my day-to-day IntelliJ. When I run my plugin, it opens up IntelliJ IDEA, but with weird fonts. The only difference in configuration is that my working IDEA is using the JetBrains JRE, and the sandboxed one is using an Oracle 1.8_151 JRE. (And that is because I can't get the sandboxed version to run on the built-in JRE, so if you know how that works, let me know also :) ). I checked all the settings in "appearance" and they are identical.
See screenshot below: the green outline is the working IntelliJ, the red outline is the sandboxed IntelliJ. Especially the JBTable looks particularly nasty.