Welcome to the Magix Sound Forge users community @vijay-n.
As @SP. stated, Please state the error code. One license can activate Sound Forge on two (2) PCs simultaneously. Use the same email address and serial code you used to activate SF the other PC. Your email address and the activation serial code are paired and must be used together.
If you purchased the subscription version (Sound Forge 365), that can only be activated on one (1) PC at a time. So if you need Sound Forge 365 on two PCs, you would need to purchase two 365 subscriptions.