Please follow below steps to active new Financial Year.

Ensure March payroll is processed and LOCK PAY PROCESS is done under 

In Paybooks 2.0: From Dashboard >> open drop down in Run Payroll button >> click on Unlock

In Paybooks 1.0Process >> Control >> Payroll

Once the above is checked, then 

In Paybooks 2.0: Go to Utilities >> under Manage Financial Year section >> click on Activate Finyear link and Select FY and click on Save

In Paybooks 1.0: Go to Configure menu >> Company Profile >> Click on Setup Rules tab >> Click on Activate Financial Year link >> Select FY and click on Save

Kindly re-login into the application and Switch Financial Year to see the effect.

New Financial Year Switch