Sorry for this mistake. It is displayed as a black block because the picture used by Bitmap font was destroyed by mistake. When _resetFrame is called, the situation of Bitmap font is not considered and the picture resource will be released. Can you confirm whether the modified custom engine is effective? You can check whether the code is modified during debugging and preview in the browser. Or you can use version 2.4.4 to test your demo. If there are still problems, you can submit your demo for verification.
Ok it worked. I didn’t edit the correct file, I edited ‘engine/cocos2d/core/components/CCLabel.js’ and “Compile Engine” but code didn’t update, so I have edited ‘engine/bin/cocos2d-js-for-preview.js’.