I was in the process of doing my period end closing and when I went Post from subledger I checked the AR Interface option and got a message that said "Invalid Accounts, Posting Not Allowed". I have been following the same process for the past three years and is the first time this message comes up. I have not added any new AR accounts and have not done anyhting out of the ordinary.

I did run the AR Distribution to GL Report and found where it said "Account Not on File" but its blank where the account number should be. How can I fix this so that I can post to the subledger? Please help.

I have received the message "Account Not Valid For A/R" before. It turned out something was posted to the wrong account in AR data entry - either invoicing or cash receipts. If you go into System Manager, System Accounts, Edit, you can see what modules are checked off for that account to be valid in.