We have enabled strict site isolation via policy to temporarily mitigate spectre. We are getting reports from across campus that users are unable to open gmail from chrome://apps or with tab restoration with the flag enabled. Console shows a DOMException. Opening gmail through a favorite or directly entering the url opens properly.

Created from report here: 

https://productforums.google.com/forum/#!topic/chrome-admins/271nj40uQ5g