When opening Screens in CRMFO you might see an error that look like this:
(Could not get Numbering Series: No matching records found (ODBC -2028))
or the error will look like this
(Could not get Numbering Series: No series were found for object <objecttype>)
These errors are normal when you have not assigned all objects in SAP Business One a numbering series (even if they are not used by CRMFO the SAP SDK can raise the errors).
So in order to fix please go to SAP and assign missing series
If still issues then also please try to restore the numbering file as that can also resolve such issues