R12 - Create Accounting is giving output as Blank

Hope you haven't selected Report parameter as "No Report".

Create Accounting has mainly two templates.

Subledger Accounting Program Report - Standard inturn calls Subledger Accounting Program Report - Sub Template.
Subledger Accounting Program Report - Sub Template is a sub template and shouldn't be used while submiting the Create Accounting.

If the output is blank, the template needs to be crosschecked, which is available in the Options Button of the SRS window.

If the template is Subledger Accounting Program Report - Sub Template, it needs to be changed to Subledger Accounting Program Report - Standard.

There is another template "Create Accounting Program Report", which will be available for 12.1.1 customers (for R12 customers by applying the patch 6868192). This generates the output from xml to the desired format quicker than the other one.