It might be needed to turn off the WProofreader plugin for CKEditor 5 while performing internal testing. For example, to avoid infinite recursion error, "RangeError: Maximum call stack size exceeded error happens", which sometimes happens in the specific configuration while using Angular. For this, not to pass our option to the CKEditor 5 start config. In the code below, do not pass 'wproofreader {...}' part from lines #5-8 to CKEditor. Just remove.
ClassicEditor .create( editorElement, { plugins: [ ..., WProofreader], toolbar: [ ..., 'wproofreader'], wproofreader: { lang: 'en_US', // sets the default language serviceId: 'your-service-ID', // required for the Cloud version only srcUrl: 'https://svc.webspellchecker.net/spellcheck31/wscbundle/wscbundle.js' } })