VSTO add-in copies assembly to weird location

  .net, caching, office365, vsto, windows

We have a VSTO word add-in, and on all machines, the assemblies are shadow copied by default to the downloads cache at C:UsersUserAppDataLocalassembly. On one specific client’s machine, this folder is never generated, and the assemblies instead get copied to C:UsersUserAppDataLocalPackagesMicrosoft.Office.Desktop_{alphanum}LocalCacheLocalassembly. However, when the app is run, when Assembly.load() is called on the assembly, it’s Location is still the above download cache, even though it doesn’t exist.

Also, the path to the downloads cache is in the registry under HKLUSOFTWAREMicrosoftFusionDownloadCacheLocation on all machines that work, but this Fusion entry doesn’t exist on the specific client’s machine. Can anybody help me answer the following, or provide steps to answer the following:

  1. Why are the assemblies copied to the Office LocalCache?
  2. Why is .NET still resolving the assembly location as the non-existant download cache?
  3. Why is the Fusion entry missing from the registry?

Source: Windows Questions