I need some help with an error

[Phil Shields]

Hi all, I'm constructing an ontology and pellet throws the following error:

An error occurred during reasoning: null.
java.lang.StackOverflowError: null
        at java.util.HashMap$KeyIterator.<init>(Unknown Source) ~[na:1.8.0_281]
        at java.util.HashMap$KeySet.iterator(Unknown Source) ~[na:1.8.0_281]
        at java.util.AbstractCollection.containsAll(Unknown Source) ~[na:1.8.0_281]
        at org.mindswap.pellet.utils.SetUtils.subset(SetUtils.java:203) ~[na:na]
        at org.mindswap.pellet.tableau.blocking.Block1.isBlocked(Block1.java:16) ~[na:na]
        at org.mindswap.pellet.tableau.blocking.OptimizedDoubleBlocking.isDirectlyBlockedBy(OptimizedDoubleBlocking.java

it looks like abstract collection contains an unknown source and is blocked? i don't know how to resolve this. At the time I was adding existential 'hasSome only' statements.

Regards,

Phil