When i am trying to open a document from document library i got an error message like a popup showing "Some files can harm your computer, If the file information below looks suspicious, or you do not fully trust the source, do not open the file".
Follow the steps to rectifiy this issue, add your site to the trusted location in browser
1) Open Internet Explorer Options à From your browser Go to “Tools” à then select “Internet Options” àthis will popups Internet Options window
2) From the Internet Options window àSelect Security Tab àHere select “Trusted Sites” Icon àClick “Sites” button
3) Again Trusted sites window will pop up àHere uncheck
4) And add http://yoursitename/ to the web sites list.
5) Now try to open the file and let us know the result.