I have experienced this several times, although I can't provide a very steady reproduce for this issue. The repro steps are something similar to below.
- Open Developer console and open a lightning component.
- Keep them idle for a while until your Salesforce account gets logged out. (I have tried manually log out and it doesn't reproduce)
- Close both your salesforce tab and developer console and re-login to Salesforce org.
- Open Developer console.
In chrome, it really opens a very small developer console window which indicates it is loading. But it is actually hang there.
IE doesn't have such an issue. The walkaround for this is to open the developer console in IE and close the lightning component file and come back to chrome it will be all sorted out.
I have experienced this issue multiple times now. Have anyone else experienced it and is it a known issue in Salesforce. I can't find a related one.