As reported by an Indonesian editor (T219851#5163519, and T219851#5166850):
I just try to publish my translation (Asuka Langley Soryu from en to id, Translation ID: 648911), but it won't let me. Even after I change the publish destination to my own user namespace. The button "Publishing..." stays in grey after clicking, and the Developer Console says this:
In Firefox:
TypeError: string is undefined load.php:2293:192 jQuery: tokenise getUnmodifiedMTPercentageInTranslationIn Chrome:
Uncaught TypeError: Cannot read property 'match' of undefined at Object.mw.cx.TranslationTracker.static.tokenise (<anonymous>:872:206) at MwCXTranslationTracker.<anonymous> (<anonymous>:881:901) at Array.forEach (<anonymous>) at MwCXTranslationTracker.mw.cx.TranslationTracker.getUnmodifiedMTPercentageInTranslation (<anonymous>:881:774) at MwCxTranslationController.mw.cx.TranslationController.checkForMTAbuse (<anonymous>:869:815) at MwCxTranslationController.mw.cx.TranslationController.publish (<anonymous>:866:183) at VeInitMwCXTarget.oo.EventEmitter.emit (<anonymous>:68:486) at VeInitMwCXTarget.ve.init.mw.CXTarget.onPublishButtonClick (<anonymous>:347:461) at VeUiCXPublishTool.ve.ui.CXPublishTool.onSelect (<anonymous>:357:477) at OoUiBarToolGroup.OO.ui.ToolGroup.onMouseKeyUp (<anonymous>:126:569)...
When I click "Publish", it just stuck. But in the console, I found "Uncaught TypeError: Cannot read property 'match' of undefined" like mentioned on the post before.
I created this link to translate a replica of the article. In my experiment, I was able to publish a translation for all the paragraphs using MT (replacing one paragraph with test text just to pass the limits). So I could not reproduce the issue initially. When edited the article further to move the test text at the end of the article in a new section, I experienced the same error mentioned above (maybe restoring the translation is a key step to reproduce the error):
Uncaught TypeError: Cannot read property 'match' of undefined at Object.mw.cx.TranslationTracker.static.tokenise (<anonymous>:872:206) at MwCXTranslationTracker.<anonymous> (<anonymous>:881:901) at Array.forEach (<anonymous>) at MwCXTranslationTracker.mw.cx.TranslationTracker.getUnmodifiedMTPercentageInTranslation (<anonymous>:881:774) at MwCxTranslationController.mw.cx.TranslationController.checkForMTAbuse (<anonymous>:869:815) at MwCxTranslationController.mw.cx.TranslationController.publish (<anonymous>:866:183) at VeInitMwCXTarget.oo.EventEmitter.emit (<anonymous>:68:486) at VeInitMwCXTarget.ve.init.mw.CXTarget.onPublishButtonClick (<anonymous>:347:461) at VeUiCXPublishTool.ve.ui.CXPublishTool.onSelect (<anonymous>:357:477) at OoUiBarToolGroup.OO.ui.ToolGroup.onMouseKeyUp (<anonymous>:126:569)