`mfc110u.dll` is a dynamic link library (DLL) file associated with the Microsoft Foundation Class (MFC) Library, specifically from Microsoft® Visual Studio® 2012. This DLL is a part of the Visual C++ redistributable package and is essential for applications developed using MFC in Visual Studio 2012. The 'u' in the filename indicates that this is a Unicode version of the library, which supports Unicode characters and is used in applications to ensure international text compatibility. MFC provides a framework for building Windows desktop applications. It wraps portions of the Windows API in C++ classes, including classes for windows, dialogs, common controls, and more. This allows developers to create rich Windows GUI applications using object-oriented techniques.

When issues occur with `mfc110u.dll`, it typically affects applications that rely on this specific version of the MFC library, leading to errors such as the application failing to start or certain features not working properly. Common causes of problems include the DLL file being missing, corrupted, or incompatible due to updates or changes to the system. To resolve issues related to `mfc110u.dll`, users can start by reinstalling the application that is experiencing the problem, which can often replace a missing or corrupted DLL file. If that doesn't resolve the issue, installing or repairing the Visual C++ 2012 Redistributable package may help, as it includes the `mfc110u.dll` file along with other necessary runtime components.