Error upgrading from to - windows 10 build 18363

hi all.
went to upgrade to the latest build today ( from using the web UI (duplicati isn’t installed as a service) and got the following error:

System.UnauthorizedAccessException: Access to the path 'agsXMPP.dll' is denied.

   at System.IO.Directory.DeleteHelper(String fullPath, String userPath, Boolean recursive, Boolean throwOnTopLevelDirectoryNotFound, WIN32_FIND_DATA& data)

   at System.IO.Directory.Delete(String fullPath, String userPath, Boolean recursive, Boolean checkHost)

   at Duplicati.Library.AutoUpdater.UpdaterManager.DownloadAndUnpackUpdate(UpdateInfo version, Action`1 progress)

after clicking install. it then offered the choice to re-download. tried it a few times and got the same error.
installed succesfully using the duplicati- version. as i’ve got it running i just thought the error output might be of use to someone.