Problem

Payment or Credit Item Types don't post to workday.  Instead they generate an error message under Review GL Messages

Solution

Most errors will fall into one of these three issues:

1) Incomplete accounting - the payment item type didn't have debit or credit specified (This is usually a setup typo)

2) The begin term & effective date had to be changed to term 1013 & 01/01/1901 .   Effective dates on item types have to fall before the actual posting of the item type.  

3) If the payment or credit item type is complete, but a charge it was paying had no GL account coding specified, so it failed to "pick up receivable from charge".  I left these item types inactive (GL Required is unchecked) but entered accounting on the GL tab. 

Specific Steps
  1. Navigate to MM > SF > GL Interface > Review GL Messages
  2. Download list of errors to MS Excel by clicking the grid icon in the upper right corner of the red header
  3. Review GL Interface Tab Item Type settings for each payment item type
  4. If the coding is bad or missing, fix the GL data.  Required: Term, Effective Date, Status, Jrnl Set, Timing, Debit/Credit, GL PCT & Jrnl Set Chartfields.  There must be a minimum of 1 Credit at 100% & 1 Debit at 100%
  5. If coding is complete, review each customer's account - looking for the payment by Item Number and check the accounting tied to the charges being satisfied.  Each item type must have account coding.  GL Required flag does not have to be set.  Enter the Accounting
  6. Let Generate GL run the following work day morning.  Check for new GL Messages.  Click search, choose the newest (topmost) instance.  If the date shown is the prior day, all issues were resolved.