Open the Windows Registry Editor on you computer (regedit)
Find the following registry path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Sstpsvc\Parameters
Add a new registry value (REG_DWORD) under called “NoCertRevocationCheck”.
Set the key value to 1 (Default is 0)
NoCertRevocationCheck
Registry path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Sstpsvc\Parameters
Name: NoCertRevocationCheck
Value: 1
Data type: REG_DWORD