Jiwa

When trying to export a GRN from Jiwa I get the following error message:
Error: Object reference not set to an instance of the object. Module Serialise
This happens if the GRN is activated or just saved

Please advise

I've reproduced the issue here and logged this for correction via bug 10814. It appears as though a ledger account entity that is used for XML serialisation is not being initialised in the code.