Api-ms-win-core-rtlsupport-l1-1-0.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like api-ms-win-core-rtlsupport-l1-1-0.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like DismHost.exe - to follow. These files were created so that multiple programs (eg. VirtualBox) could share the same api-ms-win-core-rtlsupport-l1-1-0.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 api-ms-win-core-rtlsupport-l1-1-0.dll is attempted to be loaded either when VirtualBox is starting up, or in some cases already running. Some of the most common api-ms-win-core-rtlsupport-l1-1-0.dll errors include:
- Access Violation at address - api-ms-win-core-rtlsupport-l1-1-0.dll.
- Api-ms-win-core-rtlsupport-l1-1-0.dll could not be found.
- Cannot find C:\Windows\Temp\37CEF5E8-28C2-4409-8C7D-11282D055B1B\api-ms-win-core-rtlsupport-l1-1-0.dll.
- Cannot register api-ms-win-core-rtlsupport-l1-1-0.dll.
- Cannot start VirtualBox. A required component is missing: api-ms-win-core-rtlsupport-l1-1-0.dll. Please install VirtualBox again.
- Failed to load api-ms-win-core-rtlsupport-l1-1-0.dll.
- The application has failed to start because api-ms-win-core-rtlsupport-l1-1-0.dll was not found.
- The file api-ms-win-core-rtlsupport-l1-1-0.dll is missing or corrupt.
- This application failed to start because api-ms-win-core-rtlsupport-l1-1-0.dll was not found. Re-installing the application may fix this problem.
Your api-ms-win-core-rtlsupport-l1-1-0.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with VirtualBox), or deleted by a malware infection. Furthermore, api-ms-win-core-rtlsupport-l1-1-0.dll file corruption could be caused from a power outage when loading VirtualBox, system crash while loading api-ms-win-core-rtlsupport-l1-1-0.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.