While trying to set up a new world, I encountered a crash that immediately kills the game. Here is the error itself, as seen in the log:

[Render thread/ERROR]: Reported exception thrown!
w: Rendering screen 
       at fdp.a(SourceFile:938) ~[1.19.3-pre2.jar:?] 
       at ejg.f(SourceFile:1193) ~[1.19.3-pre2.jar:?] 
       at ejg.e(SourceFile:781) ~[1.19.3-pre2.jar:?] 
       at net.minecraft.client.main.Main.a(SourceFile:244) ~[1.19.3-pre2.jar:?] 
       at net.minecraft.client.main.Main.main(SourceFile:51) ~[1.19.3-pre2.jar:?] 
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.List.stream()" because the return value of "epc$a.a()" is null 
       at epc.a(SourceFile:213) ~[1.19.3-pre2.jar:?] 
       at epc.b(SourceFile:115) ~[1.19.3-pre2.jar:?] 
       at fdp.a(SourceFile:929) ~[1.19.3-pre2.jar:?] 
       ... 4 more

This occurred specifically when I was trying to modify the game rules for a new world. In order to see if I could file a more useful bug report, I read the obfuscation map file and it seems like this has to do with tooltips. I went back in to try and see if all tooltips were affected, and my quick testing only showed one spot where the crash occurs, but it's consistent.

To reproduce the crash, it seems the offending tooltip occurs when I move my mouse from the "source lava conversion" game rule button (whose tooltip is just fine) down to the "Done" button to finish editing the game rules. The crash happens too quickly to know what exactly triggered it, but I think it's mousing over the first game rule under the next section heading. If needed I can grab a screenshot to illustrate this better. Point is, moving the mouse to the lava conversion rule and then down to the Done button should have you incidentally mouse over the problem area.