Recently encountered a bug on my latest Hexaghost run, where I equipped a Bottled Anomaly to a Sixth Seal; after successfully activating all 6 Seals and obtaining the Broken Seal the game crashes when starting an elite combat on the next floor. Restarting the game still causes a crash when the run is loaded, so the run got softlocked.

For the devs, this was the console log:
Game crashed.
Version Info:
- Java version (1.8.0_144)
- Slay the Spire (12-18-2022)
- ModTheSpire (3.30.3)
Mod list:
- basemod (5.52.2)
- stslib (2.10.0)
- downfall (4.3.2)

Mods in stacktrace:
- downfall (4.3.2)
Cause:
java.lang.NullPointerException
at guardian.relics.BottledAnomaly.atBattleStartPreDraw(BottledAnomaly.java:134)
at com.megacrit.cardcrawl.characters.AbstractPlayer.applyStartOfCombatPreDrawLogic(AbstractPlayer.java:2477)
at com.megacrit.cardcrawl.rooms.AbstractRoom.update(AbstractRoom.java:295)
at com.megacrit.cardcrawl.dungeons.AbstractDungeon.update(AbstractDungeon.java:2532)
at com.megacrit.cardcrawl.core.CardCrawlGame.update(CardCrawlGame.java:876)
at com.megacrit.cardcrawl.core.CardCrawlGame.render(CardCrawlGame.java:423)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:225)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126)

I suspect the problem is that the card I equipped the Bottled Anomaly to (Sixth Seal) is no longer in the deck, but I've procced the Broken Seal with a Bottled Anomaly Sixth Seal before with no issue so this is a bit strange.