qml_winextras.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like qml_winextras.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like MpSigStub.exe - to follow. These files were created so that multiple programs (eg. Malwarebytes) could share the same qml_winextras.dll file, saving valuable memory allocation, therefore making your computer run more efficiently.
Unfortunately, what makes DLL files so convenient and efficient, also makes them extremely vulnerable to problems. If something happens to a shared DLL file, either it goes missing or gets corrupted in some way, it can generate a "runtime" error message. Runtime is pretty self-explanatory; it means that these errors are triggered when qml_winextras.dll is attempted to be loaded either when Malwarebytes is starting up, or in some cases already running. Some of the most common qml_winextras.dll errors include:
- Access Violation at address - qml_winextras.dll.
- qml_winextras.dll could not be found.
- Cannot find C:\Program Files\Malwarebytes\Anti-Malware\QtWinExtras\qml_winextras.dll.
- Cannot register qml_winextras.dll.
- Cannot start Malwarebytes. A required component is missing: qml_winextras.dll. Please install Malwarebytes again.
- Failed to load qml_winextras.dll.
- The application has failed to start because qml_winextras.dll was not found.
- The file qml_winextras.dll is missing or corrupt.
- This application failed to start because qml_winextras.dll was not found. Re-installing the application may fix this problem.
Your qml_winextras.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Malwarebytes), or deleted by a malware infection. Furthermore, qml_winextras.dll file corruption could be caused from a power outage when loading Malwarebytes, system crash while loading qml_winextras.dll, bad sectors on your storage media (usually your primary hard drive), or quite commonly, a malware infection. Thus, it's critical to make sure your anti-virus is kept up-to-date and scanning regularly.