I have setup Office online server in standalone mode(without sharepoint or exchange server). While trying to preview document , I am able to preview excel sheets but not able to preview word or ppt files, getting error "Word online can't open this document because the service is busy, Please try again later" I am using OpenFromURLEnabled feature to test the preview. Here is the URL that generates preview link http://wacserver/op/generate.aspx.
How can we preview word and ppt document in this case?