Check antivirus first and make sure it's not scanning or interacting with the Nimsoft folders, or the folders in %APPDATA% or %TEMP% or %TMP% as this could be caused by antivirus interfering with the "write" of the package.

Also, it can help to open Internet Explorer AND clear all Temporary Internet Files, including all cache and cookies - sometimes, old/corrupted versions of probes are cached in this location and this could cause an issue downloading them.

In this case after cleaning up the temp folder it worked.

Release:
Component: CAUIM