Atom displays webdev pane on open, won't do anything else

Ack, I used to use atom extensively a few years ago and was somewhat familiar with it. Recently wanted to come back to it and was installing it on a new Windows 10 account.
I installed 15.0. And as I recall it worked fine at first. I went through the welcome guide, installed a word count package. Downloaded one or two themes. Nothing crazy. Maybe I installed another package or two but honestly i don’t remember.

The past few times I have started atom. all I get is a window with a blank white non-editable pane on the left and a panel on the right that looks like chorm webdev debugging tools, like it’s helping me debug some sort of web page.

In the menu bar I get only one menu labeled Atom with Check For Updates, Reload, Close Window, Toggle Dev Tools and Quit. Toggle Dev Tools will turn that debug pane on and off.

No idea how I got it in this state. I uninstalled and reinstalled. No help. I opened up a command prompt and started atom with atom --safe and got the same behaviour.

Looking for any guidance on how to proceed!