Do you use divisions? If you do and try to enter a customer number without including the division you could receive this error

Does the CustomerNo have any unusual characters (lowercase, dash, star, slash, pipe, invisible characters like CRLF...)?

We don't use divisions, but the system automatically assigned them.  I did enter it with the division.

Thanks

We checked for blank spaces; there are no unusual characters.  The customer number was comprised of all numbers which is unusual for our sequence. 

We also  integrated salesforce within the last year which now dictates our customer master.  This customer was created before the integration.

thanks

I've seen this error a few times after a V/I import of customers was done and in the CSV source import file, the column for the Customer No contained characters not visible as seen in Excel or Notepad.

In one case it was the CRLF that Kevin mentioned. This was visible in an advanced text editor once the Show Symbols type feature was turned on. 

In another there were odd unprintable characters when the original Excel file was saved as CSV UTF-8, as opposed to regular CSV. It was only on the 1st column of the 1st row, the rest of the data seemed fine. Only with ProvideX (not even a text editor) I could see that problem.

BTW, when you say you can bring up the customer by using the arrow keys that completely makes sense b/c the record isn't being accessed by setting the key (ARDivisionNo + CustomerNo) but rather by simply moving to the next sequential key (right arrow) or previous key (left arrow). Hope that helps.

Most common cause for invisible characters that I see is a user copy / paste of ItemCode from Excel when creating a new item (with extra CRLF)... although I think that has been fixed in recent versions.

Recently I saw a 3rd party tool change an item code to be a mix of uppercase and lowercase characters in CI_Item (causing all kinds of problems).

Of course rebuild key files is not an option with Premium, but some simple queries can check for common issues:

Our IT did run a script looking to eliminate any characters that were not visible.  It still did not work. 

Since we could not find a resolution, we were able to import a credit memo to offset the invoice (just as we imported the invoice).  Then created a new customer for the next order.  I will make all entries through the GL for this one instance.  

Thank you for your response.

I've also seen problems with accented characters (French: È, É...) used in key fields.  That should be avoided.