Thought it was alert popups operating there is an error:
Click OK to

 
# bt. Click () 
# click a button after the emergence of a popup window 
Al=browser. Switch_to. Alert 
Al. The accept () 

Error: no to window: the target window already closed
The from unknown error: web view not found

Under the window, appears in the address bar side
After other pages cannot operation, only the modal window operation
By F12 can't find this pop-up window

Excuse me: what is Google browser this pop-up window type, how to operate