Qt5WebEngineWidgets.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like Qt5WebEngineWidgets.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like calibre-eject.exe - to follow. These files were created so that multiple programs (eg. Calibre) could share the same Qt5WebEngineWidgets.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 Qt5WebEngineWidgets.dll is attempted to be loaded either when Calibre is starting up, or in some cases already running. Some of the most common Qt5WebEngineWidgets.dll errors include:
- Access Violation at address - Qt5WebEngineWidgets.dll.
- Qt5WebEngineWidgets.dll could not be found.
- Cannot find C:\Program Files (x86)\Calibre2\app\bin\Qt5WebEngineWidgets.dll.
- Cannot register Qt5WebEngineWidgets.dll.
- Cannot start Calibre. A required component is missing: Qt5WebEngineWidgets.dll. Please install Calibre again.
- Failed to load Qt5WebEngineWidgets.dll.
- The application has failed to start because Qt5WebEngineWidgets.dll was not found.
- The file Qt5WebEngineWidgets.dll is missing or corrupt.
- This application failed to start because Qt5WebEngineWidgets.dll was not found. Re-installing the application may fix this problem.
Your Qt5WebEngineWidgets.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Calibre), or deleted by a malware infection. Furthermore, Qt5WebEngineWidgets.dll file corruption could be caused from a power outage when loading Calibre, system crash while loading Qt5WebEngineWidgets.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.