Hello,
We are aware of this issue which occurs when uploading documents to SharePoint Online (Office 365) using Zetadocs Express, we believe this issue has arisen since an Office 365 update.
We have a hotfix available, if you would like this then please contact me directly (support@equisys.com). Alternatively, we will be publishing a software update on our website within a few days that will include this hotfix - I will post a link here when this is available.
Kind regards,