| Cause | Likelihood | Explanation | |-------|------------|-------------| | Running modern app on old OS | 🔴 Very High | Apps compiled with Windows 10 SDK (post-1607) call this API-set, which doesn’t exist on Windows 7/8. | | Corrupted system files | 🟡 Medium | Rare, but Windows Update issues or corruption could unregister API-sets. | | Malware/fake DLL sites | 🟢 Low (but risky) | Downloading this DLL from DLL download sites often installs malware or doesn’t fix the issue. | | Broken app installation | 🟡 Medium | App itself may be incomplete or designed for a newer Windows version. |
Modern Windows apps (UWP) rely on the App Runtime. If only specific apps (like Calculator or Photos) are crashing, re-register Windows Runtime components.
This re-registers all built-in apps and their dependencies, including the memory core libraries.
No – and doing so is dangerous.
Because this is not a real DLL but an API-set redirection, manually placing the file in System32 or the app folder will not work. The error will persist, and you risk:
🛑 Never download this DLL from any website. No official Microsoft distribution exists for it separately. api-ms-win-core-memory-l1-1-6.dll missing
| Aspect | Detail | |--------|--------| | File type | Virtual API Set contract (not a real DLL) | | Introduced | Windows 10 1809+ | | Main cause | Running new app on old Windows | | Best fix | Update Windows to latest version | | What not to do | Download DLL from shady websites |
If after a full Windows update the error persists, the application you are trying to run is likely incompatible with your current Windows edition or architecture (e.g., x64 app on x86 Windows).
If you search for this error online, you will find hundreds of websites offering a "DLL Download." They promise that if you download the file and place it in your System32 folder, the problem is solved.
Do not do this.
Downloading DLLs from third-party "DLL Dump" sites poses significant risks:
The solutions below focus on repairing the source of the dependency, ensuring your system remains secure and stable.
If you are on Windows 7 and absolutely cannot upgrade, some older software versions exist that do not require this DLL. Alternatively, using Windows 10/11 compatibility mode rarely works for this specific API, as it is a kernel-level contract, not an emulated layer.
This is the primary and most reliable fix. Modern Windows apps (UWP) rely on the App Runtime
How to install:
If you already have Service Pack 1 on Windows 7, you may also need KB2533623 (Update for Windows 7 SP1). Install it first if KB2999226 fails.
Open Command Prompt as Administrator and run:
sfc /scannow
Then run:
DISM /Online /Cleanup-Image /RestoreHealth
This repairs any broken API Set redirection mappings.