Views: 
Web Client / HTML5 Viewer:
HTML5 Viewer locks document after annotation or stamp has been set

Download Hotfix:
https://www.docuware.com/main.asp?sig=dlx&dwdblan=neutral&dwdbname=DW6_Hot12
This article is valid for DocuWare versions: 6 | hotfix dw6 html5 viewer annotation stamp #FAQID_2914