Hi SDMR,
Thanks for posting and giving details on where the error happens. This error can occur when the linked receivables or linked payables account is missing.
I recommend going to Manage linked categories and checking both the Sales and Purchases sections. Make sure an account is selected for tracking receivables and payables, then try recording the purchase again.
If both accounts are already linked and the timeout continues, it may need further investigation by support. You can reach out by creating a ticket in My Account or connecting to our live chat team through MOCA, our virtual assistant.
Regards,
Genreve