Required context insertCss was not specified in...

[elverskog]

In browser console:
Warning: Failed Context Types: Required context insertCss was not specified in WithStyles(Component). Check the render method of Main.warning @ (program):45
localhost/:62 Uncaught TypeError: Cannot read property 'apply' of undefined

[Rob-pw]

Awesome, you got there before I did.

@RickWong - This occurs on clean install, Chrome and Firefox, in addition to browser console errors (and seemingly having broken HMR) it also produces errors in terminal of:
Warning: Failed Context Types: Invalid child context styles of type object supplied to StyleProvider, expected array.

warning.js?85a7:45 Warning: Failed Context Types: Required context insertCss was not specified in WithStyles(Component). Check the render method of Main.

[Rob-pw]

@elverskog - In the meantime reverting to commit d2cb263c37310c41c81b48f609bb40779f52d0c0 will resolve the issue.

If you've not changed anything:
git checkout -f d2cb263c37310c41c81b48f609bb40779f52d0c0

[pr0fedt]

according to kriasoft/isomorphic-style-loader#5 (comment)
created a pull request #120