Cannot find window with index: '1'

[kazurayam]

You may want to update the driver version:

Unable to switch to window with index: '1'

@a.polovinkin i will let @Russ_Thomas to speak about it… but, for the current issue, as far as i understand, the root cause was a side effect of mozilla driver not being up-to-date. So, if your use case lands here, kindly try to update your web driver If not, please open new issue, it may be same or not in the case of chrome driver