Difference in "Voltus_Power_Integrity_Fi_L" && "Virtuoso_Power_System_XL"

Hi,

When i am trying to use "Voltus-Fi" , it says failed to check out "Virtuoso_Power_System_XL" license. 

I have "Voltus_Power_Integrity_Fi_L" license with me. So, want to understand why it requires "Virtuoso_Power_System_XL" license.

I am following below procedure to use "Votus-Fi".

1. Open ADE assembler

2. Run Simulation

3. Go to results -> Select one of the output(Rightclick) -> EM/IR data -> Layout Analysis

Can anyone please help to understand this.

Thanks in advance,

Amar