While experimenting with transaction dropping issue I found this (apologies if already known)
With an existing database file open, File -> New -> New File create file in same directory, say yes to overwrite existing, or create file in new different directory. Import same file as imported into initial db and...
java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:449)
at java.util.AbstractList$ListItr.set(AbstractList.java:486)
at java.util.Collections.sort(Collections.java:163)
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