This error occurs when you have the session name active (e.g., a file open) then you try to open the same session name again, even if it is a different file. You must close the session before reopening it. You can cause this error with this simple automation:

Hi @Aaron.gleason,

Thanks for the reply,

I have closed the session afor first session and inside of loop again opening excel session if I am closing the session.endless looping . If I am not closing the  session it's throwing a error.

You have a logic error somewhere. Attach a screen shot of the offending code. 

Hello Ray,

Please remove the open excel command outside the loop. Also if you to open multiple excel inside the loop use a counter variable in the session name. In order to avoid session error.

Hope this resolves your issue.

Happy Automation