IndexOutOfBoundsException on DB.commit()

[jordibuj]

We've been using MapDB on our application for years now without any issue. Now we are on version 3.0.10.
But yesterday we got this exception when committing an update:

java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
        at java.util.ArrayList.rangeCheck(ArrayList.java:659)
        at java.util.ArrayList.get(ArrayList.java:435)
        at java.util.Collections$SynchronizedList.get(Collections.java:2419)
        at org.mapdb.WriteAheadLog.walGetRecord(WriteAheadLog.java:863)
        at org.mapdb.StoreWAL$commit$4.value(StoreWAL.kt:634)
        at org.eclipse.collections.impl.map.mutable.primitive.LongLongHashMap.forEachKeyValue(LongLongHashMap.java:1066)
        at org.mapdb.StoreWAL.commit(StoreWAL.kt:633)
        at org.mapdb.DB.commit(DB.kt:435)
        at ch.mks.wta4.ui.SettingsManager.updateUserSettings(SettingsManager.java:75)
        ...

After that, some calls were ok while others gave similar errors both updating and getting data. We had to restore a backup from the day before.
Any idea on what could have caused this error?