Error Code 5 " Invalid procedure call or argument" : On Open-item Customers

Hi There

We're experiencing an error code 5 "Invalid procedure call or argument" on Pastel V19.3.5 

When selecting a customer code in the Cashbook or Journal processing screen, just as we are about to move to the next line the error is triggered.

Strangely enough this only happens on Open-item customer accounts , the error does not occur with balance forward accounts.

Troubleshooting attempts : 

  • Created new test customer account as open-item customer, error still occurs
  • Utilized fixes utility, running the "Fix Open Item Flag"
  • Rebuilt accmasd.dat, accoi.dat files
  • Reset company defaults 

Please advise on any possible solution to the query. Thank you in advance.

Regards

Nathan