Mfc140u.dll is missing from your computer. Try reinstalling the program to fix the problem. This happened with me when I had trial version of Autodesk and even when I uninstalled it and installed the licensed full version of REVIT 2017 the error remained. I have tried to remove the program with special tools, cleared registry from the program tails, erased hidden files and tried to reinstall the program once again. The installation was completed successfully, but once I launched the REVIT 2017 I immediately got mfc140u.dll is missing error. The only thing I didn’t try was to reinstall the whole operating system, but it’s just crazy to waste so much time in order to install just one program. So, this has pushed me to search for the solution on the Internet.
Mfc140u.dll is missing error happens because the program that I was trying to launch REVIT 2017 required the library to be launched and since it couldn’t find the library on my computer it just returned the error message. I double checked the system folder and couldn’t find Mfc140u.dll file there. However, this library comes by default with windows operating system, so it means that something happened in my case and the mfc140u.dll file was removed. The reasons for that are numerous, starting from virus attacks to antivirus mistaken removal due to high activity of the file. Anyway, I was able to fix mfc140u.dll is missing error in REVIT 2017 by manually installing the missing library. I went to the: http://fix4dll.com/mfc140u_dll and downloaded the genuine dll library. Afterwards I just followed the installation instructions provided here and everything started to work as intended.