When I try to edit page (on labs, as of 06 august 2017) using 2017 editor, it does not end loading (progress bar stops). It shows errors releated to codemirror, even I disable this in preferences (this may be additional issue).
```
TypeError: mwConfig is null
load.php:796:1505mediawiki.js:26:4
<anonymous> https://en.wikipedia.beta.wmflabs.org/w/
load.php:796:1505extensions/CodeMirror/resources/mode/mediawiki/mediawiki.js:26:4
getMode https://en.wikipedia.beta.wmflabs.org/w/
load.php:580:860extensions/CodeMirror/resources/lib/codemirror/lib/codemirror.js:1439:17
loadMode https://en.wikipedia.beta.wmflabs.org/w/
load.php:662:849extensions/CodeMirror/resources/lib/codemirror/lib/codemirror.js:4464:17
attachDoc https://en.wikipedia.beta.wmflabs.org/w/
load.php:665:497extensions/CodeMirror/resources/lib/codemirror/lib/codemirror.js:4562:3
CodeMirror$1 https://en.wikipedia.beta.wmflabs.org/w/
load.php:742:221extensions/CodeMirror/resources/lib/codemirror/lib/codemirror.js:7436:3
CodeMirror$1 https://en.wikipedia.beta.wmflabs.org/w/
load.php:741:155extensions/CodeMirror/resources/lib/codemirror/lib/codemirror.js:7389:49
ve.ui.CodeMirrorAction.prototype.toggle https://en.wikipedia.beta.wmflabs.org/w/
load.php:793:555extensions/CodeMirror/resources/modules/ve-cm/ve.ui.CodeMirrorAction.js:46:20
ve.ui.Surface.prototype.execute https://en.wikipedia.beta.wmflabs.org/w/
load.php:1740:550extensions/VisualEditor/lib/ve/src/ui/ve.ui.Surface.js:691:10
ve.ui.Command.prototype.execute https://en.wikipedia.beta.wmflabs.org/w/
load.php:1767:119extensions/VisualEditor/lib/ve/src/ui/ve.ui.Command.js:40:10
ve.ui.CodeMirrorTool.prototype.onSurfaceChange https://en.wikipedia.beta.wmflabs.org/w/
load.php:796:701extensions/CodeMirror/resources/modules/ve-cm/ve.ui.CodeMirrorTool.js:61:3
oo.EventEmitter.prototype.emit https://en.wikipedia.beta.wmflabs.org/w/
load.php:319:438resources/lib/oojs/oojs.jquery.js:829:5
ve.ui.Toolbar.prototype.setup https://en.wikipedia.beta.wmflabs.org/w/
load.php:1758:70extensions/VisualEditor/lib/ve/src/ui/ve.ui.Toolbar.js:76:3
ve.init.Target.prototype.setupToolbar https://en.wikipedia.beta.wmflabs.org/w/
load.php:1208:753extensions/VisualEditor/lib/ve/src/init/ve.init.Target.js:519:2
ve.init.mw.ArticleTarget.prototype.setupToolbar https://en.wikipedia.beta.wmflabs.org/w/
load.php:1141:49extensions/VisualEditor/modules/ve-mw/init/ve.init.mw.ArticleTarget.js:1813:2
ve.init.mw.DesktopArticleTarget.prototype.setupToolbar https://en.wikipedia.beta.wmflabs.org/w/
load.php:1976:29extensions/VisualEditor/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js:256:2
ve.init.Target.prototype.setSurface https://en.wikipedia.beta.wmflabs.org/w/
load.php:1208:36extensions/VisualEditor/lib/ve/src/init/ve.init.Target.js:469:3
ve.init.mw.Target.prototype.setSurface https://en.wikipedia.beta.wmflabs.org/w/
load.php:2081:528extensions/VisualEditor/modules/ve-mw/init/ve.init.mw.Target.js:408:2
ve.init.mw.DesktopArticleTarget.prototype.setSurface https://en.wikipedia.beta.wmflabs.org/w/
load.php:1980:809extensions/VisualEditor/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js:494:2
ve.init.mw.Target.prototype.setupSurface/</< https://en.wikipedia.beta.wmflabs.org/w/
load.php:2081:183extensions/VisualEditor/modules/ve-mw/init/ve.init.mw.Target.js:381:4
```