Hi, is it possible to delete all history when quitting Opera?

@imtranslator OK, so I just did so. Thanks.

Today, ImTranslator does not work as well as before. When I select several paragraphs of a web pages in a row, and then click on ImTranslator icon extension, it reacts in an unstable way, not necessarily copying my selected text to the original language window, and when it does, not necessarily putting it to clipboard for automatic translation, and/or not translating it to target language window, or if it does, limiting suddenly the selected text, in both windows, to some arbitrary limit like 869 characters... I did remove the extension 15.42 and re-install it, but got the same strange results. Is there a way to regress to earlier version ?