If you are using the AP processing integration in Purchase Plus.
Step 1. In [Settings,] [Accounts Payable,] click the [View] icon.
Step 2. Copy and paste the External URL into a word document then delete it from the External URL field (you'll need to paste it back in here later, so don't lose it!)
Step 3. In [Documents,] [Invoices,] open the Invoice that is stuck in Processing and click the yellow [Halt] button in the bottom right of the screen.
Step 4. In your Accounts Payable Hub, reinsert the External URL.
Step 5. Your Invoice will now be in a reconciled state. Open the Invoice and click on the [Process] to reprocess your Invoice.
Your Invoice will now be processed!