@jbandy
I ran into the same issue myself and did a bit of research. It appears it is a problem with the .Net Framework not using more secure SSL/TLS protocols, which can be enabled.

So, after enabling them, the very issue you have encountered above was fixed.
You have to add two registry key value in windows:

Using Powershell:

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

Or manually using regedit find:

HKey_Local_Machine\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319

Add a 32-bit DWord, called

SchUseStrongCrypto

Modify its value to 1.

Then repeat the same for:

HKey_Local_Machine\SOFTWARE\Microsoft\.NetFramework\v4.0.30319

After those values are set, you can restart the Fog service on the Windows machine, and it should work.

I hope this helps; apologies for the janky post, first time posting here. @Sebastian-Roth You may find this useful for your erratia and troubleshooting section regarding the client. It might also be possible to check and set these values via the client installer in the future.