In order to resolve an issue with a single sided journal there are a few ways of sorting this.
One way would be to use Corrections:
Find and select the Transaction in the particular Ledger.
Right-click and select Corrections
Go into the Detail lines of the transaction
Zero out the journal, set values to 0.
This should get rid of the journal. If you however cannot get rid of the journal through Corrections it will have to be deleted by support which will require a re-balance being done along with a deletion of the journal. Please give written consent to the agent you have asked to delete the Journal.
If a deletion from support is needed please raise a new case online and reference this article and please include details of the journal and the transactions affected.