How can I exit help?
I'm in a Sagemath 7.4 notebook. I click Help and choose a topic. It claims it is opening in a new "tab." Then I am stuck in help (presumably a Chromium tab) until I reboot the VirtualBox VM! If I had a keyboard shortcut to switch tabs or close the current tab, I think I'd be in business. As it stands, I'm stuck outside Sage until I reset the VM.
I've given up trying to use the Jupyter notebook. I changed the port to forward host 8888 to guest 8000, and now I see the VM listening on 8888 when I run netstat in a Windows cmd shell. Unfortunately, when I try to use a browser the page stays blank even though I do see an established connection when I run netstat on Windows.
ctrl+tab changes the tab in chromium - does this help you?