Hi,
From your error message it seems that gl account and in settings
SAP Customizing Implementation Guide > Financial Accounting (New) > General Ledger Accounting (New) > Business > ransactions > Document Splitting >Classify G/L Accounts for Document Splitting
you have assigned category 04000, which is used for cash accounts.
Also in settings,for the document type
SAP Customizing Implementation Guide > Financial Accounting (New) > General Ledger Accounting (New) > Business > ransactions > Document Splitting > Classify Document Types for Document Splitting
You have assigned Transaction 300- which is a vendor invoice, wich require vendor in the entry.
Please check your settings and the entry you want to post.
regards,
Sanju M S