Please help us help you and fill where relevant:
LimeSurvey version: 6.13.2
Own server or LimeSurvey Cloud: Own Hosted
Survey theme/template: Custom based on Vanilla
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Hi there

We have used the following plugin [url] gitlab.com/SondagesPro/QuestionSettingsType/checkboxForText [/url]  kindly provided by @Denis for almost all our projects but since upgrading to version 6 it is no longer working, I have changed the compatibility version number in the XML file and it installs but it throws an error when loading the page. 

Is there a version or an alternative to adding a Don't know button to open ended text boxes and numeric entry questions (note we run our surveys in question by question display so the manipulation of group by group wouldn't help)

Hopefully this is something that is easy to do or the plugin has a new home and has been updated.

Many thanks as always for your time
Dave