Purchases / Bills "Something Went Wrong" error message

Hello. I haven't been able to use this item on the menu for sometime. It did initially work after the upgrade but stopped about a month ago. I get around it but running a report but it is annoying. Please help me to fix it. The menu should work every time. The error message screenshot is attached.

I see that someone else had the same issue and was advised to go to Accounting / Manage Linked Accounts / Purchases and check that the correct liability account is listed. I have done this. Screenshot attached. It did not solve the issue. I tried linking to another account, saving, then changing back. Problem not fixed.

The next part of the previous advice was to access code and send it in. I don't understand the instructions that person was given so can't do anymore at this stage. Please advise.