Posting error message "Account No. Not exist, not allow to post"

As per the issue below, please check the following:

 

Post to Accounting > Preview > if you see the following “*” symbol, it’s due to GL Account did not map in.

 

Billing Module > Housekeeping > Run Setup > General Setup > Account No > Please map in the Gl Account.

 

 

You can post once you have map in the GL Account.