What that error message states is that there is no credit account set. And as you know every transaction must have a debit and credit. When using the NV1 style transactions NewViews automatically inputs JOURNAL_BAL as the credit account. Sometimes these defaults are cleared. To restore this back to the default setting delete the current transaction that is causing the error and run a default setup on your journal.
The default setup can be accomplished by right clicking on the blue title bar, where it should say something in this manner (/JOURNAL/GENERAL/GENERAL – NV1 Style Transcations). After right clicking on the blue bar a menu will pop up, hit the + on window and select default setup.
After performing the default setup return to the NV1 Style transactions and try to create a transaction, hopefully the issue will be resolved.