I want to make an A/P entry but it says the vender HG12 doesn't exist.
Where are the necessary settings so that I can post to that particular vendor.

You need to maintained the following settings before you can post:

1. Creation of Vendor Account Groups(OBD3) 

2. Create Number Ranges For Vendor Account Group(XKN1) 

3. Assign Number Ranges For Vendor Account Group(OBAS) 

4. Define Tolerance Groups For Vendor/Customer Groups(OBA3) 

5. Creation of Sundry Creiditors Accounts(FS00) 

6. Creation of Vendor Master(XK01) 

7. Define Number Ranges For Postings(FBN1)
 

How to resolve this error, while making a payment to vendor.  I have invoice amount document credit to vendor and debit adjustment document as debit to vendor, its not allowing for net off , getting the error has "Enter a payment method for incoming payments".

You can do any of the following:

1. Delete the existing payment proposal.  Clear the debit, credit by offsetting which will create a new net due document. Then run F110.

or

2. Delete the existing payment proposal. Configure and incoming payment method for the company code and then run F110.

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