Currently, the option for "Use a single AR Summary Account and never post Applications" is marked in Accounts Receivable > Configuration > Business Rules > General.

We only recommend using this business rule if
(1) You use an AR summary account in a fund that does NOT require projects or transaction codes on balance sheet accounts,
(2) You do NOT require balancing by account segment
(3) You can use Unrestricted Net Assets as the single net asset class value for all Accounts Receivable transactions.

If any of the above do apply to your setup, and you have certain balancing requirements in place you may need to choose the option to use multiple AR summary accounts instead:

1. From the Accounts Receivable Configuration page click Business Rules
2. Highlight the General option
3. Unmark the 'Use a single AR Summary Account and never post Applications' checkbox

*We do not recommend changing your net asset class or switching between one and multiple AR summary accounts once activity has been entered.

For more information, check out "How to select, turn off, or not require to use the Suspense Account" and the Default Accounts section of the  Accounts Receivable Configuration Guide