Office 16/Office 365 potential issues with CCleaner [under investigation] in CCleaner Bug Reporting Posted November 22, 2019 Hi SO, I am still having this problem too. I have also had it corrupt Excel as well. My way around it is I have Word, Excel, Outlook, Powerpoint open at the time of running ccleaner, and this has prevented the corruption happening. It of course has its own limitations on clearing recent file histories etc for these applications. When I have forgotten to open these before running ccleaner it occasionally again corrupts the files and needs re-installation. I have always taken One Drive off and this has never been installed whilst I have had these problems. @scoobydog , yes I am puzzled by the lack of progress on this, I wonder it is even on the to-do list?