mclmcrrt9-9.dll is a core component of the MATLAB Runtime (MCR) , specifically corresponding to MATLAB R2015b
Win + R, type sysdm.cpl → Advanced → Environment Variables.Path → Edit → Verify entry.If the app you are trying to run came with its own "redistributable" or "installer" package, try running that setup file again. It may have failed to extract the DLL correctly during the first installation. ⚠️ A Note on Safety Never download individual DLL files mclmcrrt9-9.dll
Search for "Edit the system environment variables" in your Start menu. Click Environment Variables. Under "System variables," find Path and click Edit. mclmcrrt9-9