Need help on error Keyboard Locked

Hi

I have created Vuser script using RTE protocol for AS400 application and it replayed successfully for one user and I created a scenario using Performance Center 11.5 and tried executing for 2 users but i am getting the below errors

TE_type failed text =to <region> <kEnter>, keyboard locked

Error Waiting 20s before existing user.

Kindly help on the above errors.

Regards

Rama