Unable to establish DDE connection after Reader DC 2017.009.20044

We use the DDE API to control print jobs in Acrobat and Reader.  This morning, all machines that updated to Reader DC 2017.009.20044 fail to establish the DDE connection.  The call works fine on all versions prior to 2017.009.20044.

We have disabled both "Enable Protected Mode at Startup" and "Enable Enhanced Security".

We are using topic = "Control"

We have attempted to establish the connection with the following service names:

AcroView

AcroviewR10

AcroviewR11

AcroviewR12

AcroviewR13

AcroviewR14

AcroviewR15

In each case, we get DMLERR_NO_CONV_ESTABLISHED (0x400a) from the call to DdeConnect()

Our app is written in C, but we've also confirmed failure with VBA code:

Public Sub test()

    Dim hdde As Long

    hdde = DDEInitiate("AcroViewR10", "Control")

    Debug.Print hdde

    DDETerminate hdde

End Sub

While I'm at it, we'd prefer to not use DDE for this at all, but we have been unable to find a COM API call that allows us to initiate a print job to a specific print service.  We are using [FilePrintTo(%s, %s, %s, %s)] - if anyone has guidance on a COM call that would replace the FilePrintTo DDE call, we'd gladly move away from DDE.  AcroExch.AVDoc.PrintPagesSilent(), for example, only prints to the current printer, which won't work for us.