Error 280 Unable to copy file "..\..\AjaxControlToolkit.Binary.NET35\fr\AjaxControlToolkit.resources.dll"

Error 280 Unable to copy file "..\..\AjaxControlToolkit.Binary.NET35\fr\AjaxControlToolkit.resources.dll" to "bin\fr\AjaxControlToolkit.resources.dll". Access to the path 'bin\fr\AjaxControlToolkit.resources.dll' is denied. ProjectName


Delete all ajax related (or all) files/folders in bin folder.
Rebuild project.
New files/folders with corrected permissions will be created.