On Windows Server 2019 Core, Unified Communications Managed API 4.0 Runtime fails to install. The error log says:
0320.08A8::10/23/2018-14:43:43.024 Log file opened.
0320.08A8::10/23/2018-14:43:43.024 LOGGING STARTED
0320.08A8::10/23/2018-14:43:43.024 Creating data folder.
0320.08A8::10/23/2018-14:43:43.040 64 Bit Setup is running, checking for NOX86
0320.08A8::10/23/2018-14:43:43.040 NOX86 length : '0'
0320.08A8::10/23/2018-14:43:43.040 Checking preconditions.
0320.08A8::10/23/2018-14:43:43.055 GetLibraryVersion for shdocvw.dll failed.
0320.08A8::10/23/2018-14:43:43.055 Getting ready to exit.
0320.08A8::10/23/2018-14:43:43.055 Deleting temporary setup files
0320.08A8::10/23/2018-14:43:45.014 ENDED LOGGING
This can clearly not work because shdocvw.dll is not part of the Windows Core product.