I wanted to post this link to a KB article titled Why do I receive a script error when trying to execute the Developer Console? I found which may or may not be helpful to those who are trying to troubleshoot problems with their Dev Consoles.
The IDEWorkspace is accessible through Workbench using the REST explorer. If you have the Id of the IDEworkspace, you can view the contents of your IDEworkspace and delete any problematic contents. Support tells me the first thing to do with problematic Dev Consoles is to delete ALL logs. When I did that, it didn't work for me, but might for others. More importantly, the article suggests to me that there's much about the Dev Console that can be explored by various means if one has the knowledge, time and interest.
In my experience, if the Dev Console won't open, you want to try to delete the history of what it's trying to put in the console for you in the default view from the last session. That was the issue I was having from having been working with Lightning components. I couldn't get a debug session going in the child window to even obtain the Id of my workspace (Chrome browser). What eventually worked for me, was repeatedly trying have a Lightning component file open up in the Dev Console from the list of components in setup that I'd already created. Eventually, that cleared out the corrupted history of what should open up by default in the console, allowing the console to open for me with the file I'd selected.
Hope this helps someone else with any issues they're having.