The official Oracle Documentation states that you have to install the Microsoft Visual C++ Redistributable 2012 (VC++ 11.0), but with this Version you will hit the FRM-93552 error message while calling your Forms.
You will need to install the Microsoft Visual C++ Redistributable 2010 (VC++ 10.0), which you can find under following link https://www.microsoft.com/en-us/download/details.aspx?id=14632
Just install the above mentioned version of the Microsoft Visual C++ Redistributable 2010, you can have multiple version of the Microsoft Visual C++ Redistributable package at the same time on your server.
After the installation of the Microsoft Visual C++ Redistributable 2010 simple stop and start your Managed Server for Oracle Forms and the problem with the FRM-93552 error is gone.