In Sitefinity 4.4.2117 there is no such problem which was present in Sitefinity 4.0, however this problem will return an error log that might contain more information what is causing this.
Clear the log files(and save them in another folder) in App_Data/Sitefinity/Logs and go to change a document. An error log must be generated after a short time. If no log is generated examine the current request that the replacing of the image or document generates with firebug`s net tab and see if some request fails. If it does you can capture a service trace that will log information by modifying web.config of the project as described in this
All the best,
the Telerik team
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