I updated to QT 5.2.1 recently. My Application run perfectly in debug mode but in release mode it is looking for icuin49.dll. Which is not there in the C:\Qt\Qt5.2.1\5.2.1\mingw48_32\bin folder.It has only icuin51.dll .I guess in debug mode the Qt5xxxxxd.dll is called up and is looking for the actual icuin51.dll and in release mode it is looking for the old one.Does any one has this issue.Please help me out.