Based on your comments I suspect you tried to import directly into the history tables.  Did you import into Invoice Data Entry and then post or did you import into the AP Invoice History and Detail History files.  Also have you checked to make sure you posted the Daily Transaction Register?  Go to General Ledger, Main, Daily Transaction Register and try to post and see what happens.

We import using an AP import job in the visual integrator, then we go to invoice register to post. We have done this every period closing.The invoices can be pulled up in Vendor Maintenance. When I Alt-Z into an invoice, I can see that the entry is posted in a Source Journal under the Main tab. When I Zoom into the Source Journal, it shows what ledger accounts the invoices are posted to. However, when I check the ledger accounts in Account Maintenance in General Journal, they don’t appear to be posted there.

We import using an AP import job in the visual integrator, then we go to invoice register to post. We have done this every period closing.The invoices can be pulled up in Vendor Maintenance. When I Alt-Z into an invoice, I can see that the entry is posted in a Source Journal under the Main tab. When I Zoom into the Source Journal, it shows what ledger accounts the invoices are posted to. However, when I check the ledger accounts in Account Maintenance in General Journal, they don’t appear to be posted there.

This sounds kinda like you posted in the wrong year. Pull up the journal again and look at the year